OFFSET
1,2
COMMENTS
Union of sums of k-th powers, for k >= 1.
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
Michael Penn, an excruciatingly deep dive into the power sum., YouTube video, 2022.
EXAMPLE
30 is in the set because 30 = 1^2 + 2^2 + 3^2 + 4^2 (j=2, k=4).
MAPLE
N:= 1000: # to get all terms <= N
A:=select(`<=`, {1, seq(seq(sum(i^k, i=1..m), m=2..floor((N*(k+1))^(1/(k+1)))), k = 1 ..ilog2(N-1))}, N):
sort(convert(A, list)); # Robert Israel, Jan 26 2015
MATHEMATICA
Take[ Union[ Flatten[ Table[ Sum[ i^j, {i, 1, n}], {j, 1, 9}, {n, 1, 40}]]], 60]
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Apr 18 2003
EXTENSIONS
Corrected and extended by Robert G. Wilson v, May 08 2003
STATUS
approved