A097240 a(n) = (n+1)*prime(n) + n*prime(n+1).

7, 19, 41, 79, 131, 193, 269, 355, 491, 629, 779, 973, 1133, 1303, 1547, 1845, 2099, 2365, 2689, 2951, 3265, 3643, 4039, 4553, 5047, 5405, 5773, 6155, 6547, 7313, 8125, 8707, 9245, 9931, 10649, 11239, 11997, 12703, 13427, 14253, 14939, 15805, 16703

Offset: 1

Author

Reinhard Zumkeller, Aug 02 2004

Keywords

• nonn

Comments

Of the first 10000 terms, 1540 are primes. - Antti Karttunen, Jul 30 2022

Links

• Antti Karttunen, Table of n, a(n) for n = 1..10000
• Index entries for sequences computed from indices in prime factorization

Crossrefs

Cf. A000040, A006094, A097241 (primes in this sequence), A258851.

Column 3 of A356155.

Programs

Mathematica

Table[(n+1)Prime[n]+n*Prime[n+1],{n,50}] (* Harvey P. Dale, Oct 02 2017 *)

PARI

A097240(n) = ((n+1)*prime(n) + n*prime(n+1)); \\ Antti Karttunen, Jul 30 2022

Formula

a(n) = A258851(A006094(n)). - Antti Karttunen, Jul 30 2022