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A027965 T(n, 2*n-3), T given by A027960. 3
3, 7, 15, 28, 47, 73, 107, 150, 203, 267, 343, 432, 535, 653, 787, 938, 1107, 1295, 1503, 1732, 1983, 2257, 2555, 2878, 3227, 3603, 4007, 4440, 4903, 5397, 5923, 6482, 7075, 7703, 8367, 9068, 9807, 10585, 11403, 12262, 13163, 14107, 15095, 16128, 17207, 18333, 19507, 20730, 22003 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,1

LINKS

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

Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1).

FORMULA

a(n+2) = A074742(n-1) = A008778(n) + 2 = A000297(n-1) + 3.

From Ralf Stephan, Feb 07 2004: (Start)

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

Differences of A027966. (End)

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

a(n) = (18 - 10*n + 3*n^2 + n^3)/6.

E.g.f.: (-18 - 12*x + (18 - 6*x + 6*x^2 + x^3)*exp(x))/6. (End)

MATHEMATICA

LinearRecurrence[{4, -6, 4, -1}, {3, 7, 15, 28}, 50] (* G. C. Greubel, Jun 30 2019 *)

PROG

(PARI) vector(50, n, n++; (18-10*n+3*n^2+n^3)/6) \\ G. C. Greubel, Jun 30 2019

(MAGMA) [(18-10*n+3*n^2+n^3)/6: n in [2..50]]; // G. C. Greubel, Jun 30 2019

(Sage) [(18-10*n+3*n^2+n^3)/6 for n in (2..50)] # G. C. Greubel, Jun 30 2019

(GAP) List([2..50], n-> (18-10*n+3*n^2+n^3)/6) # G. C. Greubel, Jun 30 2019

CROSSREFS

A column of triangle A027011.

Sequence in context: A103021 A025587 A101498 * A130145 A023552 A293316

Adjacent sequences:  A027962 A027963 A027964 * A027966 A027967 A027968

KEYWORD

nonn

AUTHOR

Clark Kimberling

EXTENSIONS

Terms a(32) onward added by G. C. Greubel, Jun 30 2019

STATUS

approved

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Last modified August 12 12:23 EDT 2020. Contains 336439 sequences. (Running on oeis4.)