A307647 Numbers that are the sum of a prime number and a positive cube.

3, 4, 6, 8, 10, 11, 12, 13, 14, 15, 18, 19, 20, 21, 24, 25, 27, 29, 30, 31, 32, 34, 37, 38, 39, 40, 42, 44, 45, 46, 48, 49, 50, 51, 54, 55, 56, 58, 60, 61, 62, 64, 66, 67, 68, 69, 70, 71, 72, 74, 75, 77, 79, 80, 81, 83, 84, 86, 87, 88, 90, 91, 93, 94, 95, 97, 98, 100, 101, 102, 104, 105

Offset

1,1

Links

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

Formula

Exponents in expansion of (Sum_{i>=1} x^prime(i)) * (Sum_{j>=1} x^(j^3)).

Maple

N:= 200: # for terms <= N
P:= select(isprime, [2, seq(i, i=3..N-1, 2)]):
C:= [seq(j^3, j=1..floor((N-2)^(1/3)))]:
sort(convert(select(`<=`, {seq(seq(p+c, p=P), c=C)}, N), list)); # Robert Israel, Apr 22 2019

Crossrefs

Cf. A000040, A000578, A058654, A211167, A283760, A307646.

Sequence in context: A135251 A298809 A335194 * A088070 A175071 A336822

Adjacent sequences: A307644 A307645 A307646 * A307648 A307649 A307650

Keyword

nonn

Author

Ilya Gutkovskiy, Apr 19 2019

Status

approved