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A014309 a(n) = (n+2)*(n+1)*(n^2 + 7*n - 12)/24. 1
-1, 3, 15, 40, 84, 154, 258, 405, 605, 869, 1209, 1638, 2170, 2820, 3604, 4539, 5643, 6935, 8435, 10164, 12144, 14398, 16950, 19825, 23049, 26649, 30653, 35090, 39990, 45384, 51304, 57783, 64855, 72555 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..725

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

FORMULA

G.f.: x*(1 + x^4 - 5*x^3 + 10*x^2 - 8*x)/(x-1)^5. - Maksym Voznyy (voznyy(AT)mail.ru), Aug 10 2009

E.g.f.: (24 - (24 - 48*x^2 - 16*x^3 - x^4)*exp(x))/24. - G. C. Greubel, Jun 12 2019

MATHEMATICA

Table[(n+2)(n+1)(n^2+7n-12)/24, {n, 40}]  (* Harvey P. Dale, Feb 20 2011 *)

PROG

(MAGMA) [(n+2)*(n+1)*(n^2+7*n-12)/24: n in [1..40]]; // Vincenzo Librandi, Apr 25 2011

(PARI) {a(n) = (n+2)*(n+1)*(n^2+7*n-12)/24}; \\ G. C. Greubel, Jun 12 2019

(Sage) [(n+2)*(n+1)*(n^2+7*n-12)/24 for n in (1..40)] # G. C. Greubel, Jun 12 2019

(GAP) List([1..40], n-> (n+2)*(n+1)*(n^2+7*n-12)/24) # G. C. Greubel, Jun 12 2019

CROSSREFS

Sequence in context: A146853 A183476 A297621 * A298049 A298884 A298655

Adjacent sequences:  A014306 A014307 A014308 * A014310 A014311 A014312

KEYWORD

sign

AUTHOR

N. J. A. Sloane

STATUS

approved

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Last modified October 22 04:25 EDT 2019. Contains 328315 sequences. (Running on oeis4.)