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A140431 2*A094555(n). 7
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 (list; graph; refs; listen; history; text; internal format)
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: A194767 A202669 A178845 * A092900 A164961 A122007

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

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Last modified August 17 03:38 EDT 2017. Contains 290631 sequences.