11
votes
Calculate Pi unto a point using the Nilakantha series
Python 3.8 (pre-release), 38 bytes (@xnor)
f=lambda n,i=.5:i//n/n or 2/i-f(n,i+1)
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Python 3.8 (pre-release), 40 bytes (@xnor)
...
- 9,318
7
votes
Accepted
The "Fly straight, dammit" sequence
05AB1E, 12 bytes
1‚λDN¿DiNOë÷
Outputs the infinite sequence.
Try it online.
Explanation:
...
- 109k
7
votes
IMO Question Six with a difference
Python, 49 bytes
f=lambda n,a=1:a>n+1or(n*n-2)%~(a*(a+n))*f(n,a+1)
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Outputs Truthy/Falsey reversed.
Checks whether $$\frac{n^2-2}{a(a+n)+1}$$ is ...
- 139k
6
votes
Number of ways to make an amount with coins
JavaScript (ES6), 41 bytes
Saved 3 bytes thanks to @ovs
f=(n,k=10)=>n?k*n>0&&f(n,k>>1)+f(n-k,k):1
Try it online!
40 bytes
Suggested by @tsh
...
- 171k
6
votes
The "Fly straight, dammit" sequence
C (GCC), 65 bytes
t,r;h(a,b){r=b?h(b,a%b):a;}c(n){n=n<2?:h(t=c(n-1),n)<2?t-~n:t/r;}
Attempt This Online!
This is based on py3programmer's answer; I'm posting ...
- 22.6k
6
votes
Calculate Pi unto a point using the Nilakantha series
JavaScript (ES6), 32 bytes
This version is based on @loopy-walt's answer, golfed by @xnor.
f=(n,i=.5)=>i<n?2/i-f(n,i+1):1/n
Try it online!
JavaScript (ES6),...
- 171k
6
votes
Accepted
Calculate Pi unto a point using the Nilakantha series
Jelly, 13 bytes
RḤrƝP€4÷Ṛḅ-+3
A monadic Link that accepts a positive integer and yields the approximation (up to the floating point accuracy).
Try it online!
How?
<...
- 93.9k
6
votes
Count the number of compositions of \$n\$ in which the greatest part is odd
Python, 58 bytes
f=lambda n,m=0:sum(f(k,max(m,n-k))for k in range(n))or m%2
Try it online!
An exponential solution that implicitly generates all compositions by ...
- 139k
5
votes
Sums of Consecutive Integers
K (ngn/k), 40 32 bytes
{^/!'1+i@'*>-/i:&x=s-\:s:+\!1+x}
Try it online!
-8 bytes thanks to @ngn
- 361
5
votes
Find the nth Mersenne Prime
JavaScript (ES6), 50 bytes
Returns the \$n\$-th Mersenne prime, 1-indexed.
n=>{for(k=1;n;n-=d<2)for(d=k-=~k;k%--d;);return k}
Try it online!
...
- 171k
5
votes
Calculate Pi unto a point using the Nilakantha series
Factor + koszul math.unicode, 68 64 bytes
[ ""3 rot [0,b) [ -1^ 4 reach Π / * + [ 2 v+n ] dip ] each ]
Attempt This ...
- 11.5k
5
votes
Calculating Pi using the Gregory Leibniz series until n terms
05AB1E, 14 9 bytes
L·<z··R®β
-5 bytes porting @JonathanAllan's Jelly answer
Try it online or verify all test cases.
Original 14 bytes answer:
...
- 109k
5
votes
Calculating Pi using the Gregory Leibniz series until n terms
Python 3, 36 35 bytes
f=lambda n,k=1:n and 4/k-f(n-1,k+2)
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-1 thanks to Mukundan314.
- 7,661
5
votes
Count the number of compositions of \$n\$ in which the greatest part is odd
Python, 92 bytes
g=[17*[1,-1]]
r=range(33)
for i in r:g+=[sum(y[~k:])for*y,k in zip(*g,r)],;print(sum(g[-1]))
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Prints 33 terms.
How?
First ...
- 9,318
4
votes
Get the length of a Sumac Sequence
Ruby, 25 bytes
f=->a,b{a>0?f[b,a-b]+1:0}
Attempt This Online!
- 311
4
votes
Find the nth Mersenne Prime
Factor + math.primes.lucas-lehmer, 48 bytes
[ 1 lfrom [ lucas-lehmer ] lfilter lnth 2^ 1 - ]
Try it online!
0-indexed.
...
- 11.5k
4
votes
Accepted
Find the nth Mersenne Prime
Vyxal G, 7 bytes
Þ∞E‹~æẎ
Try it Online!
7 bytes flagless (change Ẏ to ...
- 23.7k
4
votes
Number of ways to make an amount with coins
HOPS, 20 bytes
mset(x+x^2+x^5+x^10)
Attempt This Online!
- 37.6k
4
votes
Accepted
Number of ways to make an amount with coins
Vyxal, 12 8 7 bytes
Ṅ₀$ḊvΠ∑
Try it Online!
6 bytes with s flag
Explained
...
- 23.7k
4
votes
Number of ways to make an amount with coins
Wolfram Language (Mathematica), 36 bytes
Length[{1,2,5,10}~FrobeniusSolve~#]&
Try it online!
- 23.3k
4
votes
Number of ways to make an amount with coins
Regex 🐇 (RME / Perl / PCRE / Raku:P5), 24 bytes
^x*(xx)*(x{5})*(x{10})*$
Takes its input ...
- 10.2k
4
votes
The "Fly straight, dammit" sequence
Prolog (SWI), 68 56 bytes
-12 bytes thanks to @Steffan
N+X:-N>1,N-1+B,C=gcd(B,N),(C<2,X is B+N+1;X is B/C);X=1.
Try it online!
- 8,455
4
votes
Calculating Pi using the Gregory Leibniz series until n terms
C (gcc), 63 60 bytes
float f(n){float m=4,p=1,d=1;for(;n--;d+=2,m=-m)p+=m/d;--p;}
Try it online!
Saved 3 bytes thanks to jdt!!!
- 18.8k
4
votes
Accepted
Calculating Pi using the Gregory Leibniz series until n terms
Jelly, 8 bytes
RḤ’4÷Ṛḅ-
A monadic Link that accepts a positive integer, \$n\$, and yields a floating point number, \$\pi_n\$.
Try it online!
How?
...
- 93.9k
4
votes
Count the number of compositions of \$n\$ in which the greatest part is odd
05AB1E, 15 11 bytes
Åœ€œ€`Ù€àÉO
-4 bytes outputting the \$n^{th}\$ value instead of mapping over the ranged list \$[1,33]\$
Outputs as a list.
Very slow, and will ...
- 109k
4
votes
Count the number of compositions of \$n\$ in which the greatest part is odd
x86-64 machine code, 27 bytes
31 C9 48 0F AB F9 6A 01 58 99 89 CF 41 F7 D2 8D 34 3F 21 F7 75 F7 29 D0 E2 EF C3
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Following the standard calling ...
- 7,661
3
votes
All together now
Prolog (SWI), 40 bytes
\[A|S]:-S=[];(S=[A|_];\+member(A,S)),\S.
Try it online!
-3 thanks to Jo King
Similar to xnor's second Haskell answer.
This won't work on TIO ...
- 10.9k
3
votes
Product of Divisors
Vyxal, 2 bytes
KΠ
Explanation:
K # Gets the divisors of a number
Π # Product of array
Try it Online!
- 199
3
votes
3
votes
Sums of Consecutive Integers
K (ngn/k), 61 41 bytes
h:{i{x':y}\:i:1+!x}
f:{i@*|&x=+/'i:,/h@x}
Try it online!
¯20 bytes thanks to @doug
- 1,654
Only top scored, non community-wiki answers of a minimum length are eligible