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A027969 a(n) = T(n, 2*n-7), T given by A027960. 3
3, 7, 18, 47, 120, 291, 661, 1404, 2801, 5283, 9484, 16305, 26990, 43215, 67191, 101782, 150639, 218351, 310614, 434419, 598260, 812363, 1088937, 1442448, 1889917, 2451243, 3149552, 4011573, 5068042, 6354135, 7909931, 9780906, 12018459, 14680471, 17831898, 21545399, 25902000, 30991795 (list; graph; refs; listen; history; text; internal format)
OFFSET

4,1

LINKS

G. C. Greubel, Table of n, a(n) for n = 4..1000

Index entries for linear recurrences with constant coefficients, signature (8,-28,56,-70,56,-28,8,-1).

FORMULA

From Ralf Stephan, Feb 07 2004: (Start)

G.f.: x^4*(3-2x)*(1-x+x^2)*(1-4x+7x^2-4x^3+x^4)/(1-x)^8.

First differences of A027970. (End)

From G. C. Greubel, Jul 01 2019: (Start)

a(n) = (90720 -85548*n +38822*n^2 -10136*n^3 +1505*n^4 -77*n^5 -7*n^6 + n^7)/5040.

E.g.f.: (-90720 - 35280*x - 7560*x^2 - 1680*x^3 + (90720 - 55440*x + 17640*x^2 - 3360*x^3 + 630*x^4 - 42*x^5 + 14*x^6 + x^7)*exp(x))/5040. (End)

MATHEMATICA

Table[(90720 -85548*n +38822*n^2 -10136*n^3 +1505*n^4 -77*n^5 -7*n^6 + n^7)/5040, {n, 4, 50}] (* G. C. Greubel, Jul 01 2019 *)

PROG

(PARI) for(n=4, 50, print1((90720 -85548*n +38822*n^2 -10136*n^3 +1505*n^4 -77*n^5 -7*n^6 + n^7)/5040, ", ")) \\ G. C. Greubel, Jul 01 2019

(MAGMA) [(90720 -85548*n +38822*n^2 -10136*n^3 +1505*n^4 -77*n^5 -7*n^6 + n^7)/5040: n in [4..50]]; // G. C. Greubel, Jul 01 2019

(Sage) [(90720 -85548*n +38822*n^2 -10136*n^3 +1505*n^4 -77*n^5 -7*n^6 + n^7)/5040 for n in (4..50)] # G. C. Greubel, Jul 01 2019

(GAP) List([4..50], n-> (90720 -85548*n +38822*n^2 -10136*n^3 +1505*n^4 -77*n^5 -7*n^6 + n^7)/5040) # G. C. Greubel, Jul 01 2019

CROSSREFS

A column of triangle A027011.

Sequence in context: A094297 A026107 A173765 * A027971 A219233 A211276

Adjacent sequences:  A027966 A027967 A027968 * A027970 A027971 A027972

KEYWORD

nonn

AUTHOR

Clark Kimberling

EXTENSIONS

Terms a(35) onward added by G. C. Greubel, Jul 01 2019

STATUS

approved

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Last modified August 12 12:20 EDT 2020. Contains 336439 sequences. (Running on oeis4.)