A140721 Alternated reading of A000302 and negated A002042.

1, -7, 4, -28, 16, -112, 64, -448, 256, -1792, 1024, -7168, 4096, -28672, 16384, -114688, 65536, -458752, 262144, -1835008, 1048576, -7340032, 4194304, -29360128, 16777216, -117440512, 67108864, -469762048, 268435456, -1879048192, 1073741824

Offset

0,2

Comments

Sequence can also be obtained by negating the first differences of A135520: a(n)=A135520(n)-A135520(n+1).

Links

Table of n, a(n) for n=0..30.

Formula

a(2n) = A000302(n). a(2n+1) = -A002042(n) .

a(2n) = -7a(2n-1). a(2n)-a(2n-1) = A002089(n-1). a(n)+a(n+1) = -3*A135520(n).

O.g.f.: (7x-1)/((2x-1)(2x+1)). - R. J. Mathar, Jul 14 2008

Crossrefs

Sequence in context: A282449 A282608 A070427 * A281750 A282365 A281896

Adjacent sequences: A140718 A140719 A140720 * A140722 A140723 A140724

Keyword

sign,less

Author

Paul Curtz, Jul 12 2008

Extensions

Edited by R. J. Mathar, Jul 14 2008

Status

approved