A071992 a(n) = 3*n^2 + 2*n - 4 * Sum_{k=1..n} A003159(k).

1, 0, 1, 4, 5, 4, 1, 0, 1, 0, 1, 4, 5, 8, 13, 16, 17, 16, 17, 20, 21, 20, 17, 16, 17, 16, 13, 8, 5, 4, 1, 0, 1, 0, 1, 4, 5, 4, 1, 0, 1, 0, 1, 4, 5, 8, 13, 16, 17, 16, 17, 20, 21, 24, 29, 32, 37, 44, 49, 52, 53, 56, 61, 64, 65, 64, 65, 68, 69, 68, 65, 64, 65, 64, 65, 68, 69, 72, 77, 80

Offset

1,4

Comments

0 <= a(n) <= n for any n.

Links

Table of n, a(n) for n=1..80.

Robert G. Wilson v, Illustration of initial terms

Formula

For any k, a(A062880(k)) = 0; a(A000695(k))=A000695(k)

Crossrefs

Cf. A000695, A003159, A062880.

Sequence in context: A258197 A255698 A290558 * A291845 A322193 A174984

Adjacent sequences: A071989 A071990 A071991 * A071993 A071994 A071995

Keyword

easy,nonn

Author

Benoit Cloitre, Jun 17 2002

Status

approved