A180637 Digital root of A179899.

0, 3, 3, 3, 9, 3, 3, 6, 3, 3, 9, 3, 9, 3, 3, 6, 3, 3, 6, 3, 9, 3, 9, 3, 6, 3, 3, 3, 9, 3, 6, 9, 3, 6, 3, 9, 3, 3, 6, 9, 3, 3, 6, 3, 6, 3, 9, 3, 9, 3, 3, 6, 9, 3, 3, 3, 6, 9, 3, 6, 3, 6, 9, 3, 6, 3, 3, 9, 3, 3, 6, 9, 3, 9, 3, 9, 3, 9, 3, 3, 6, 3, 3, 6, 9, 3, 9, 3, 6, 9, 3, 6, 3, 3, 9, 3, 6, 9, 3, 6, 3, 6, 3, 6, 9

Offset

1,2

Comments

Every term after the first is 3, 6, or 9.

Links

Nathaniel Johnston, Table of n, a(n) for n = 1..10000

Maple

ithnonprime := proc(n)local k: option remember: if(n=1)then return 1: else k := procname(n-1)+1: while true do if(not isprime(k))then return k fi: k:=k+1: od: fi: end: A179899ind := proc(n) option remember: local k: if(n=1)then return 1:fi: for k from procname(n-1)+1 do if(ithnonprime(k) mod 2 <> 0)then return k: fi: od: end: A180637 := proc(n) if(n=1)then return 0:fi: return ((3*(ithnonprime(A179899ind(n))-1)/2 - 1) mod 9) + 1: end: seq(A180637(n), n=1..100); # Nathaniel Johnston, May 05 2011

Crossrefs

Cf. A179899.

Sequence in context: A329694 A183389 A275530 * A362376 A201539 A223747

Adjacent sequences: A180634 A180635 A180636 * A180638 A180639 A180640

Keyword

easy,nonn,base

Author

Odimar Fabeny, Sep 13 2010

Extensions

Edited by Nathaniel Johnston, May 05 2011

Status

approved