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A126944 The sequence a[n]+b[n]+c[n]+d[n] defined in A126939. 1
1, 5, 15, 47, 149, 469, 1477, 4657, 14677, 46251, 145765, 459391, 1447783, 4562753, 14379751, 45318455, 142823219, 450114149, 1418555997, 4470646047, 14089451907, 44403572399, 139939952691, 441027361411, 1389918532165, 4380393813543, 13805017716305 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..26.

FORMULA

Empirical g.f.: -(x^5 +2*x^4 +5*x^3 +4*x^2 +3*x +1) / (x^6 +3*x^5 +3*x^4 +7*x^3 +x^2 +2*x-1). - Colin Barker, Apr 08 2013

MATHEMATICA

a[0] = 1; a[1] = 5; a[2] = 15; a[3] = 47; a[4] = 149; a[5] = 469; a[n_] := a[n] = a[n-6] + 3*a[n-5] + 3*a[n-4] + 7*a[n-3] + a[n-2] + 2*a[n-1]; Table[a[n], {n, 0, 26}] (* Jean-Fran├žois Alcover, Nov 23 2016 *)

LinearRecurrence[{2, 1, 7, 3, 3, 1}, {1, 5, 15, 47, 149, 469}, 27] (* or *)

CoefficientList[ Series[-(x^5 + 2x^4 + 5x^3 + 4x^2 + 3x + 1)/(x^6 + 3x^5 + 3x^4 + 7x^3 + x^2 + 2x -1), {x, 0, 26}], x] (* Robert G. Wilson v, Nov 23 2016 *)

CROSSREFS

Sequence in context: A089040 A331237 A184262 * A077841 A126945 A191641

Adjacent sequences:  A126941 A126942 A126943 * A126945 A126946 A126947

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Mar 18 2007

STATUS

approved

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Last modified October 27 01:02 EDT 2020. Contains 338035 sequences. (Running on oeis4.)