The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A014792

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A014792

Squares of even heptagonal numbers.
(history; published version)

#19 by Andrew Howroyd at Sun Oct 06 17:27:35 EDT 2019

STATUS

reviewed

approved

#18 by Michel Marcus at Sun Oct 06 17:15:45 EDT 2019

STATUS

proposed

reviewed

#17 by Jon E. Schoenfield at Sun Oct 06 16:46:24 EDT 2019

STATUS

editing

proposed

#16 by Jon E. Schoenfield at Sun Oct 06 16:46:21 EDT 2019

FORMULA

a(n) = (1/2)*(200*n^4 - 120*n^3 + 18*n^2) for n even.

a(n) = (1/2)*(200*n^4 + 280*n^3 + 138*n^2 + 28*n + 2) for n odd.

G.f.: 4*x*(81 + 208*x + 2523*x^2 + 1508*x^3 + 4071*x^4 + 680*x^5 + 525*x^6 + 4*x^7) / ((1-x)^5*(1+x)^4).

EXTENSIONS

More terms from Patrick De Geest, Aug 17 2000.

STATUS

approved

editing

#15 by Alois P. Heinz at Thu Dec 17 06:58:39 EST 2015

STATUS

proposed

approved

#14 by Colin Barker at Thu Dec 17 06:24:11 EST 2015

STATUS

editing

proposed

Discussion

Thu Dec 17

06:58

Alois P. Heinz: ok.

#13 by Colin Barker at Thu Dec 17 06:23:55 EST 2015

PROG

(PARI) concat(0, Vec(4*x*(81+208*x+2523*x^2+1508*x^3+4071*x^4+680*x^5+525*x^6+4*x^7) / ((1-x)^5*(1+x)^4) + O(x^40))) \\ Colin Barker, Dec 17 2015

STATUS

proposed

editing

#12 by Colin Barker at Thu Dec 17 06:23:22 EST 2015

STATUS

editing

proposed

#11 by Colin Barker at Thu Dec 17 06:20:42 EST 2015

EXTENSIONS

More terms from Patrick De Geest, 08/Aug 17 2000.

Discussion

Thu Dec 17

06:23

Colin Barker: I invented a valid date for the extension.

#10 by Colin Barker at Thu Dec 17 06:18:37 EST 2015

DATA

0, 324, 1156, 12544, 21904, 81796, 116964, 291600, 379456, 763876, 940900, 1658944, 1971216, 3175524, 3678724, 5550736, 6310144, 9060100, 10150596, 14017536, 15523600, 20775364, 22791076, 29724304, 32353344, 41293476, 44649124, 55950400, 60155536, 74200996

LINKS

Colin Barker, <a href="/A014792/b014792.txt">Table of n, a(n) for n = 0..1000</a>

<a href="/index/Rec#order_09">Index entries for linear recurrences with constant coefficients</a>, signature (1,4,-4,-6,6,4,-4,-1,1).

FORMULA

From Colin Barker, Dec 17 2015: (Start)

a(n) = 1/2*(200*n^4-120*n^3+18*n^2) for n even.

a(n) = 1/2*(200*n^4+280*n^3+138*n^2+28*n+2) for n odd.

G.f.: 4*x*(81+208*x+2523*x^2+1508*x^3+4071*x^4+680*x^5+525*x^6+4*x^7) / ((1-x)^5*(1+x)^4).

(End)

PROG

(PARI) concat(0, Vec(4*x*(81+208*x+2523*x^2+1508*x^3+4071*x^4+680*x^5+525*x^6+4*x^7)/((1-x)^5*(1+x)^4) + O(x^40))) \\ Colin Barker, Dec 17 2015

KEYWORD

nonn,easy

STATUS

approved

editing