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A141397
a(n) = 3*a(n-1) + A001651(n+1).
1
1, 5, 19, 62, 193, 587, 1771, 5324, 15985, 47969, 143923, 431786, 1295377, 3886151, 11658475, 34975448, 104926369, 314779133, 944337427, 2833012310, 8499036961, 25497110915, 76491332779, 229473998372, 688421995153, 2065265985497, 6195797956531, 18587393869634
OFFSET
0,2
COMMENTS
Row sums of triangle A141396.
FORMULA
G.f.: ( -1-x-x^2 ) / ( (1+x)*(3*x-1)*(x-1)^2 ). a(n) = (-1)^n/16 -3*n/4 -3/2 +13*3^(n+1)/16. - R. J. Mathar, Feb 16 2011
EXAMPLE
a(2) = 19 = 3*a(1) + A001651(3) = 3*5 + 4 where A001651(3) = 4.
a(2) = 19 = sum of row 2 terms of triangle A141396: (4 + 6 + 9).
MATHEMATICA
LinearRecurrence[{4, -2, -4, 3}, {1, 5, 19, 62}, 50] (* Harvey P. Dale, Jul 07 2024 *)
PROG
(PARI) Vec((-1-x-x^2) / ((1+x)*(3*x-1)*(x-1)^2) + O(x^40)) \\ Michel Marcus, Jan 21 2015
CROSSREFS
Sequence in context: A072111 A173627 A295288 * A305779 A143131 A036677
KEYWORD
nonn,easy
AUTHOR
Gary W. Adamson, Jun 29 2008
STATUS
approved