A297199 a(n) = number of partitions of n into consecutive positive cubes.
1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
Offset: 1
Keywords
Examples
1 = 1^3, so a(1) = 1. 8 = 2^3, so a(8) = 1. 9 = 1^3 + 2^3, so a(9) = 1. 27 = 3^3, so a(27) = 1. 35 = 2^3 + 3^3, so a(35) = 1. 36 = 1^3 + 2^3 + 3^3, so a(36) = 1. 64 = 4^3, so a(64) = 1. 91 = 3^3 + 4^3, so a(91) = 1. 99 = 2^3 + 3^3 + 4^3, so a(99) = 1. 100 = 1^3 + 2^3 + 3^3 + 4^3, so a(100) = 1.
Links
- Antti Karttunen, Table of n, a(n) for n = 1..65537 (terms 1..10000 from Robert Israel)
Programs
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Maple
N:= 200: # to get a(1)..a(N) F:= (a, b) -> (b^2*(b+1)^2-a^2*(a-1)^2)/4: A:= Vector(N): for b from 1 to floor(N^(1/3)) do for a from b to 1 by -1 do v:= F(a,b); if v > N then break fi; A[v]:= A[v]+1; od od: convert(A,list); # Robert Israel, Jan 15 2018, corrected Jan 29 2018
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PARI
A297199(n) = { my(s=0, k=1, c); while((c=k^3) <= n, my(u=n-c, i=k); while(u>0, i++; c = i^3; u=u-c); s += (!u); k++); (s); }; \\ Antti Karttunen, Aug 22 2019
Formula
a(A217843(n)) >= 1 for n > 1.
a(n) >= 2 for n in A265845. - Robert Israel, Jan 15 2018
G.f.: Sum_{i>=1} Sum_{j>=i} Product_{k=i..j} x^(k^3). - Ilya Gutkovskiy, Apr 18 2019