A100481 Greatest prime factor in A095117(n).

1, 3, 5, 3, 2, 3, 11, 3, 13, 7, 2, 17, 19, 5, 7, 11, 3, 5, 3, 7, 29, 5, 2, 11, 17, 7, 3, 37, 13, 5, 7, 43, 11, 5, 23, 47, 7, 5, 17, 13, 3, 11, 19, 29, 59, 5, 31, 7, 2, 13, 11, 67, 23, 7, 71, 3, 73, 37, 19, 11, 79, 5, 3, 41, 83, 7, 43, 29, 11, 89, 13, 23, 47, 19, 3, 97, 7, 11, 101, 17, 103

Offset: 1

Author

Jonathan Vos Post, Nov 22 2004

Keywords

• easy
• nonn
• less

Comments

Conjecture: every prime appears infinitely often in this sequence.

Crossrefs

Cf. A000720, A006530, A095117.

Programs

PARI

gpf(n) = if (n==1, 1, vecmax(factor(n)[,1]));
a(n) = gpf(n + primepi(n)); \\ Michel Marcus, Feb 24 2023

Formula

a(n) = A006530(n + A000720(n)).

Extensions

Extended by Ray Chandler, Nov 27 2004