A014156 Numbers that are not the sum of a nonnegative cube and a triangular number.

5, 12, 13, 17, 19, 20, 24, 25, 26, 31, 32, 34, 35, 38, 39, 40, 41, 43, 47, 49, 50, 51, 52, 54, 57, 58, 59, 60, 61, 62, 68, 69, 71, 73, 75, 76, 77, 80, 81, 83, 84, 87, 88, 89, 90, 94, 95, 96, 97, 98, 101, 102, 103, 104, 107, 108, 110, 111, 112, 114, 115, 116, 117, 122

Offset

1,1

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Maple

N:= 200: # for terms <= N
nC:= floor(surd(N, 3)): C:= {seq(i^3, i=0..nC)}:
nT:= floor((sqrt(1+8*N)-1)/2): T:= {seq(i*(i+1)/2, i=0..nT)}:
A:= {$1..N} minus select(`<=`, {seq(seq(c+t, c=C), t=T)}, N):
sort(convert(A, list)); # Robert Israel, Apr 17 2026

Mathematica

Complement[Range[0, 1000], Union[Flatten[Outer[Plus, Table[n^3, {n, 0, 10}], Table[n(n+1)/2, {n, 0, 50}]]]]]

Crossrefs

Cf. A014155 (complement).

Sequence in context: A076537 A263580 A110134 * A367355 A367621 A114073

Adjacent sequences: A014153 A014154 A014155 * A014157 A014158 A014159

Keyword

nonn

Author

N. J. A. Sloane

Extensions

Corrected and extended by Dean Hickerson, Aug 30 2001

Status

approved