A076562 a(1)=3; a(n>1)= greatest prime divisor of a(n-1) + n.

3, 5, 2, 3, 2, 2, 3, 11, 5, 5, 2, 7, 5, 19, 17, 11, 7, 5, 3, 23, 11, 11, 17, 41, 11, 37, 2, 5, 17, 47, 13, 5, 19, 53, 11, 47, 7, 5, 11, 17, 29, 71, 19, 7, 13, 59, 53, 101, 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

Offset

1,1

Comments

Starting with 4th term the sequence coincides with sequence with a(1)=2. Also starting with 49th term both sequence coincide with the sequence with a(1)=1! Surprisingly, the sequence with a(1)=4&5 also coincide with all above sequence starting with 49th term.

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, 3}, 80]][[2]] (* Harvey P. Dale, Apr 14 2015 *)

Crossrefs

Sequence in context: A059246 A091276 A282574 * A306220 A057673 A279398

Adjacent sequences: A076559 A076560 A076561 * A076563 A076564 A076565

Keyword

easy,nonn

Author

Zak Seidov, Oct 19 2002

Status

approved