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a(n) = 3*a(n-1) + A001651(n+1).
1

%I #16 Jul 07 2024 17:44:17

%S 1,5,19,62,193,587,1771,5324,15985,47969,143923,431786,1295377,

%T 3886151,11658475,34975448,104926369,314779133,944337427,2833012310,

%U 8499036961,25497110915,76491332779,229473998372,688421995153,2065265985497,6195797956531,18587393869634

%N a(n) = 3*a(n-1) + A001651(n+1).

%C Row sums of triangle A141396.

%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (4,-2,-4,3)

%F 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

%e a(2) = 19 = 3*a(1) + A001651(3) = 3*5 + 4 where A001651(3) = 4.

%e a(2) = 19 = sum of row 2 terms of triangle A141396: (4 + 6 + 9).

%t LinearRecurrence[{4,-2,-4,3},{1,5,19,62},50] (* _Harvey P. Dale_, Jul 07 2024 *)

%o (PARI) Vec((-1-x-x^2) / ((1+x)*(3*x-1)*(x-1)^2) + O(x^40)) \\ _Michel Marcus_, Jan 21 2015

%Y Cf. A141396, A001651.

%K nonn,easy

%O 0,2

%A _Gary W. Adamson_, Jun 29 2008