A307647 - OEIS

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

(list; graph; refs; listen; history; text; internal format)

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