A004886 Numbers that are the sum of at most 2 positive 9th powers.

0, 1, 2, 512, 513, 1024, 19683, 19684, 20195, 39366, 262144, 262145, 262656, 281827, 524288, 1953125, 1953126, 1953637, 1972808, 2215269, 3906250, 10077696, 10077697, 10078208, 10097379, 10339840, 12030821, 20155392, 40353607, 40353608

Offset

1,3

Links

Zhuorui He, Table of n, a(n) for n = 1..10000

Prog

(Python)
def A004886_upto(n):
  a=set()
  for i in range(n):
    if 2*(i**9)>n: break
    for j in range(i, n):
      if i**9+j**9<=n: a.add(i**9+j**9)
      else: break
  return sorted(a) # Zhuorui He, Jun 30 2025
(PARI) lista(nn) = setbinop((x, y)->x^9+y^9, [0..nn]); \\ Michel Marcus, Jul 02 2025

Crossrefs

Cf. A001017 (9th powers), A003391 (sum of 2).

Sequence in context: A109032 A362539 A109111 * A234606 A139302 A003391

Adjacent sequences: A004883 A004884 A004885 * A004887 A004888 A004889

Keyword

nonn

Author

N. J. A. Sloane

Status

approved