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A027966 T(n, 2*n-4), T given by A027960. 3
1, 4, 11, 26, 54, 101, 174, 281, 431, 634, 901, 1244, 1676, 2211, 2864, 3651, 4589, 5696, 6991, 8494, 10226, 12209, 14466, 17021, 19899, 23126, 26729, 30736, 35176, 40079, 45476, 51399, 57881, 64956, 72659, 81026, 90094, 99901, 110486, 121889, 134151, 147314, 161421, 176516, 192644 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,2

LINKS

G. C. Greubel, Table of n, a(n) for n = 2..1000

Index entries for linear recurrences with constant coefficients, signature (5,-10,10,-5,1).

FORMULA

From Ralf Stephan, Feb 07 2004: (Start)

G.f.: x^2*(1 - x + x^2 + x^3 - x^4)/(1-x)^5.

Differences of A027967. (End)

From G. C. Greubel, Jun 30 2019: (Start)

a(n) = (n^4 + 2*n^3 - 25*n^2 + 94*n - 96)/24.

E.g.f.:  (96 +24*x - (96 - 72*x + 12*x^2 - 8*x^3 - x^4)*exp(x))/24. (End)

MATHEMATICA

LinearRecurrence[{5, -10, 10, -5, 1}, {1, 4, 11, 26, 54}, 50] (* G. C. Greubel, Jun 30 2019 *)

PROG

(PARI) vector(50, n, n++; (n^4+2*n^3-25*n^2+94*n-96)/24) \\ G. C. Greubel, Jun 30 2019

(MAGMA) [(n^4+2*n^3-25*n^2+94*n-96)/24: n in [2..50]]; // G. C. Greubel, Jun 30 2019

(Sage) [(n^4+2*n^3-25*n^2+94*n-96)/24 for n in (2..50)] # G. C. Greubel, Jun 30 2019

(GAP) List([2..50], n-> (n^4+2*n^3-25*n^2+94*n-96)/24) # G. C. Greubel, Jun 30 2019

CROSSREFS

A column of triangle A026998.

Sequence in context: A077270 A076048 A109414 * A141534 A320852 A192961

Adjacent sequences:  A027963 A027964 A027965 * A027967 A027968 A027969

KEYWORD

nonn

AUTHOR

Clark Kimberling

EXTENSIONS

Terms a(31) onward added by G. C. Greubel, Jun 30 2019

STATUS

approved

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Last modified February 23 15:00 EST 2020. Contains 332166 sequences. (Running on oeis4.)