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A006323 4-dimensional analog of centered polygonal numbers. 4
1, 10, 41, 115, 260, 511, 910, 1506, 2355, 3520, 5071, 7085, 9646, 12845, 16780, 21556, 27285, 34086, 42085, 51415, 62216, 74635, 88826, 104950, 123175, 143676, 166635, 192241, 220690, 252185, 286936, 325160, 367081, 412930 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

FORMULA

a(n) = 7*C(n + 2, 4) + C(n + 1, 2).

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

MATHEMATICA

CoefficientList[Series[(-1 - x^2 - 5 x) / (x - 1)^5, {x, 0, 40}], x] (* Vincenzo Librandi, Sep 06 2013 *)

PROG

(PARI) a(n) = 7*binomial(n + 2, 4) + binomial(n + 1, 2); \\ Michel Marcus, Sep 05 2013

(MAGMA) [7*Binomial(n+2, 4)+Binomial(n+1, 2): n in [1..40]]; // Vincenzo Librandi, Sep 06 2013

CROSSREFS

Sequence in context: A022278 A246972 A266396 * A178073 A102784 A294604

Adjacent sequences:  A006320 A006321 A006322 * A006324 A006325 A006326

KEYWORD

nonn,easy

AUTHOR

Albert Rich (Albert_Rich(AT)msn.com)

EXTENSIONS

G.f. adapted to the offset by Vincenzo Librandi, Sep 06 2013

STATUS

approved

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Last modified October 22 21:09 EDT 2018. Contains 316505 sequences. (Running on oeis4.)