A076560 a(1)=1; a(n>1)= greatest prime divisor of (a(n-1) + n).

1, 3, 3, 7, 3, 3, 5, 13, 11, 7, 3, 5, 3, 17, 2, 3, 5, 23, 7, 3, 3, 5, 7, 31, 7, 11, 19, 47, 19, 7, 19, 17, 5, 13, 3, 13, 5, 43, 41, 3, 11, 53, 3, 47, 23, 23, 7, 11, 5, 11, 31, 83, 17, 71, 7, 7, 2, 5, 2, 31, 23, 17, 5, 23, 11, 11, 13, 3, 3, 73, 3, 5, 13, 29, 13, 89, 83, 23, 17, 97, 89, 19

Offset

1,2

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Mathematica

nxt[{n_, a_}]:={n+1, FactorInteger[a+n+1][[-1, 1]]}; Transpose[NestList[nxt, {1, 1}, 90]][[2]] (* Harvey P. Dale, Nov 29 2013 *)

Prog

(PARI) gpf(n) = if(n==1, 1, my(v=factor(n)[, 1]); v[#v]);
a_vector(len) = my(t=0); vector(len, n, t=gpf(t+n)); \\ Kevin Ryde, Jun 21 2023

Crossrefs

Cf. A006530 (gpf), A362138.

Sequence in context: A367034 A366982 A366973 * A359048 A096915 A249806

Adjacent sequences: A076557 A076558 A076559 * A076561 A076562 A076563

Keyword

easy,nonn

Author

Zak Seidov, Oct 19 2002

Extensions

Definition clarified by Harvey P. Dale, Nov 29 2013

Status

approved