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a(n) = 2^n + n*(n+3).
1

%I #14 Mar 05 2022 01:02:24

%S 1,6,14,26,44,72,118,198,344,620,1154,2202,4276,8400,16622,33038,

%T 65840,131412,262522,524706,1049036,2097656,4194854,8389206,16777864,

%U 33555132,67109618

%N a(n) = 2^n + n*(n+3).

%C Row sums of triangle A131950.

%H <a href="/index/Rec">Index entries for linear recurrences with constant coefficients</a>, signature (5,-9,7,-2).

%F Binomial transform of (1, 5, 3, 1, 1, 1, ...).

%F G.f. ( 1+x-7*x^2+3*x^3 ) / ( (2*x-1)*(x-1)^3 ). - _R. J. Mathar_, Apr 04 2012

%e a(3) = 26 = sum of row 3 terms, triangle A131950: (7 + 6 + 6 + 7).

%e a(3) = 26 = (1, 3, 3, 1) dot (1, 5, 3, 1) = (1 + 15 + 9 + 1).

%Y Cf. A131950.

%K nonn,easy

%O 0,2

%A _Gary W. Adamson_, Jul 30 2007

%E New definition by _R. J. Mathar_, Apr 04 2012