A140431 2*A094555(n).

0, 2, 2, 12, 22, 92, 222, 772, 2102, 6732, 19342, 59732, 175782, 534172, 1588862, 4793892, 14327062, 43090412, 129052782, 387595252, 1161911942, 3487483452, 10458955102, 31383855812, 94137586422, 282440721292, 847266239822

Offset

0,2

Links

Table of n, a(n) for n=0..26.

Index entries for linear recurrences with constant coefficients, signature (2,5,-6).

Formula

b(n) = A091002(n-1); b(n+1)-3b(n)= A077925(n-2), where b(n)=floor(a(n)/10).

a(n) = (1-(-2)^n+3^n)/3 for n>0. a(n) = 2*a(n-1)+5*a(n-2)-6*a(n-3) for n>3. G.f.: 2*x*(1-x-x^2)/((1-x)*(1+2*x)*(1-3*x)). [Colin Barker, Sep 21 2012]

Crossrefs

Sequence in context: A346757 A202669 A178845 * A092900 A303537 A369086

Adjacent sequences: A140428 A140429 A140430 * A140432 A140433 A140434

Keyword

nonn,walk,easy

Author

Paul Curtz, Jun 19 2008

Extensions

Edited and extended by R. J. Mathar, Aug 02 2008

Status

approved