A154890 Jacobsthal numbers A001045 alternatingly incremented by 3 and 5.

3, 6, 4, 8, 8, 16, 24, 48, 88, 176, 344, 688, 1368, 2736, 5464, 10928, 21848, 43696, 87384, 174768, 349528, 699056, 1398104, 2796208, 5592408, 11184816, 22369624, 44739248, 89478488, 178956976, 357913944, 715827888, 1431655768, 2863311536, 5726623064

Offset

0,1

Links

Table of n, a(n) for n=0..34.

Formula

a(2n+1) = 2*a(2n).

a(n) = A153643(n)+A010684(n).

a(n+2) = 4*A128209(n).

a(n) = 2*a(n-1)+a(n-2)-2*a(n-3). G.f.: (3-11x^2)/((1-x)(1+x)(1-2x)). [R. J. Mathar, Jan 23 2009]

Crossrefs

Sequence in context: A136612 A004546 A197255 * A248176 A100000 A083682

Adjacent sequences: A154887 A154888 A154889 * A154891 A154892 A154893

Keyword

nonn,easy

Author

Paul Curtz, Jan 17 2009

Extensions

Edited and extended by R. J. Mathar, Jan 23 2009

Status

approved