A158233 a(n) = A120070(n+1)*A120070(n+2) mod 9.

6, 4, 3, 0, 3, 6, 0, 3, 0, 0, 4, 0, 0, 4, 6, 0, 0, 6, 0, 6, 0, 0, 6, 3, 0, 3, 6, 3, 4, 0, 0, 4, 0, 0, 4, 0, 0, 6, 3, 0, 3, 6, 0, 0, 3, 0, 0, 6, 0, 6, 0, 0, 3, 3, 6, 4, 0, 0, 4, 0, 0, 4, 0, 0, 4, 3, 0, 3, 0, 0, 0, 3, 0, 6, 6, 0, 3, 6, 0, 3, 0, 0, 0, 3, 0, 6, 6, 0, 3, 0, 0, 4, 0, 0, 4, 0, 0, 4, 0, 0, 4, 0, 0, 4, 6

Offset

1,1

Comments

Conjecture: this contains only the numbers 0,3,4,6 (verified for the first 5000 terms).

This multiply-modulo transformation is also used in the unrelated A157742, A158012, A158068, A158090.

Links

Table of n, a(n) for n=1..105.

Maple

A120070 := proc(m, n) if m-1 >= n then m^2-n^2; else 0; fi; end:
A120070flat := proc(n) i := 2 ; for m from 2 do for l from 1 to m-1 do if i = n then RETURN(A120070(m, l)) ; else i := i+1 ; fi; od: od: end:
A158233 := proc(n) (A120070flat(n+1)*A120070flat(n+2) ) mod 9 ; end: seq(A158233(n), n=1..180) ; # R. J. Mathar, Apr 09 2009

Crossrefs

Sequence in context: A019849 A244685 A118421 * A093604 A011408 A350094

Adjacent sequences: A158230 A158231 A158232 * A158234 A158235 A158236

Keyword

nonn

Author

Paul Curtz, Mar 14 2009

Extensions

Edited and extended by R. J. Mathar, Apr 09 2009

Status

approved