A113958
Triangular numbers that can be written as sum of two positive cubes.
DATA
28, 91, 351, 2926, 8001, 46971, 58653, 93528, 97461, 141778, 300700, 365085, 382375, 398278, 874503, 1295245, 1669878, 3425653, 4117015, 7517503, 7657741, 7771653, 9415630, 9598771PYTHON IMPLEMENTATION
No Python implementation recorded in the local database yet.
PROGRAMS
Mathematica
Sort[Select[Total/@Subsets[Range[300]^3,{2}],OddQ[Sqrt[8#+1]]&]] (* _Harvey P. Dale_, Oct 10 2014 *)
Other Programs
- (PARI) :
T=thueinit('z^3+1);
has(n)=#select(v->min(v[1],v[2])>0, thue(T,n))>0
list(lim)=my(v=List()); for(n=7,(sqrtint(lim\1*8+1)-1)\2, my(t=n*(n+1)/2); if(has(t), listput(v,t))); Vec(v) \\ _Charles R Greathouse IV_, May 22 2026
COMMENTS
EXAMPLES
- 91 = 13*(13+1)/2 = 4^3 + 3^3, therefore 91 is a term.
LINKS
- Donovan Johnson, Table of n, a(n) for n = 1..5122
- Index entries for sequences related to sums of cubes
CROSSREFERENCES
- Cf. A000217, A000578, A003108, A003325, A119977.
- See also the official entry at https://oeis.org/A113958
METADATA
- OFFSET :
1,1 - KEYWORDS :
nonn - AUTHOR : Reinhard Zumkeller, Jun 03 2006
- IDENTIFICATION :
#16 May 22 2026 23:59:10