A094359 Pair reversal of a Jacobsthal sequence.

0, 1, 2, 2, 10, 6, 42, 22, 170, 86, 682, 342, 2730, 1366, 10922, 5462, 43690, 21846, 174762, 87382, 699050, 349526, 2796202, 1398102, 11184810, 5592406, 44739242, 22369622, 178956970, 89478486, 715827882, 357913942, 2863311530, 1431655766

Offset: 0

Author

Paul Barry, Apr 26 2004

Keywords

• easy
• nonn

Comments

Pair reversal of A078008.

Pisano period lengths: 1, 1, 6, 1, 4, 6, 6, 2, 18, 4, 10, 6, 12, 6, 12, 2, 8, 18, 18, 4, ... - R. J. Mathar, Aug 10 2012

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..1000
• Index entries for linear recurrences with constant coefficients, signature (-1,4,4).

Crossrefs

Cf. A078008, A084183, A094360.

Programs

Magma

[5*2^n/12-2*(-1)^n/3+(-2)^n/4: n in [0..35]]; // Vincenzo Librandi, Aug 12 2011

Formula

a(n) = 5*2^n/12 - 2(-1)^n/3 + (-2)^n/4.

G.f.: x*(1+3*x)/((1+x)*(1-4*x^2)).

a(n+1) - 2*a(n) = A000918(n) signed. - Paul Curtz, Jun 29 2008