OFFSET
1,2
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
Jean-Christophe Pain, A prime sum involving Bernoulli numbers, arXiv:2303.07934 [math.HO], 2023. See (22) p. 4.
Eric Weisstein's World of Mathematics, Prime Sums.
FORMULA
a(n) = (1/4)*(prime(n)-2)*(prime(n)-1)*(prime(n)+1).
MATHEMATICA
Table[(Times@@(Prime[n]+{1, -1, -2}))/4, {n, 40}] (* Harvey P. Dale, Dec 31 2020 *)
PROG
(PARI) a(n) = my(p=prime(n)); sum(k=1, p-1, k^3\p); \\ Michel Marcus, Mar 16 2023
CROSSREFS
KEYWORD
nonn
AUTHOR
Benoit Cloitre, Dec 08 2002
STATUS
approved