A141446 A102055(n) mod 9.

1, 2, 1, 4, -4, 7, -5, 8, -5, 4, -7, 1, -5, 5, -2, 4, -1, 4, -5, 2, -8, 4, -4, 7, -5, 8, -5, 4, -7, 1, -5, 5, -2, 4, -1, 4, -5, 2, -8, 4, -4, 7, -5, 8, -5, 4, -7, 1, -5, 5, -2, 4, -1, 4, -5, 2, -8, 4, -4, 7, -5, 8, -5, 4, -7, 1, -5, 5, -2, 4, -1, 4, -5, 2, -8, 4, -4, 7, -5, 8, -5, 4, -7, 1, -5, 5

Offset: 0

Author

Paul Curtz, Aug 07 2008

Keywords

• sign

Comments

We compute the positive remainder modulo 9 and subtract 9 if A102055(n) is negative.

Appears to be periodic with period length 18 after the transitional first 3 elements. (This would imply only the same 6 digits appear as found in A141425.)

Crossrefs

Cf. A141430.

Programs

Maple

A102055 := proc(n) local k; if n = 0 then 1; else 1-add(A001469(k),k=1..n) ; end if; end proc:
A141446 := proc(n) local a; a := A102055(n) ; if a > 0 then a mod  9; else (a mod  9)-9; end if; end proc; # R. J. Mathar, Jul 07 2011

Formula

a(3n) + a(3n+1) + a(3n+2) = 4, 7, -2, -2, -2, 5 ever same six digits?