A127064 a(0)=1. a(n) = a(prime(n)(mod n)) + 1, where prime(n) is the n-th prime.

1, 2, 3, 4, 5, 3, 3, 5, 5, 4, 5, 5, 3, 4, 3, 4, 4, 6, 6, 6, 6, 6, 5, 4, 7, 6, 5, 6, 5, 6, 5, 5, 5, 4, 5, 5, 6, 5, 6, 6, 5, 5, 5, 7, 7, 7, 5, 5, 6, 6, 7, 7, 6, 7, 6, 6, 7, 6, 7, 6, 6, 7, 8, 7, 7, 8, 8, 8, 9, 4, 5, 5, 6, 4, 5, 6, 5, 6, 6, 4, 5, 4, 6, 5, 5, 4, 5, 4, 7, 5, 5, 4, 7, 6, 7, 8, 5, 8, 6, 6, 6, 6, 6, 7, 7

Offset

0,2

Links

Table of n, a(n) for n=0..104.

Example

The 7th prime, 17, is congruent to 3 (mod 7). So a(7) = a(3) + 1 = 4 + 1 = 5.

Maple

a[0]:=1: for n from 1 to 125 do a[n]:=1+a[ithprime(n) mod n] od: seq(a[n], n=0..125); # Emeric Deutsch, Mar 25 2007

Mathematica

f[l_List] := Block[{n = Length[l]}, Append[l, l[[Mod[Prime[n], n] + 1]] + 1]]; Nest[f, {1}, 105] (* Ray Chandler, Mar 25 2007 *)

Prog

(PARI) a(n)={k=1; if(n>0, k=a(prime(n)%n)+1); k; } \\ Jinyuan Wang, Feb 01 2019

Crossrefs

Cf. A004648, A127066.

Sequence in context: A343252 A341355 A104413 * A279850 A117607 A215092

Adjacent sequences: A127061 A127062 A127063 * A127065 A127066 A127067

Keyword

nonn

Author

Leroy Quet, Mar 21 2007

Extensions

Extended by Ray Chandler and Emeric Deutsch, Mar 25 2007

Status

approved