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

Author

N. J. A. Sloane

Keywords

• nonn

Links

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

Crossrefs

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

Programs

PARI

lista(nn) = setbinop((x,y)->x^9+y^9, [0..nn]); \\ Michel Marcus, Jul 02 2025

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