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A253514 Centered heptagonal numbers (A069099) which are also centered octagonal numbers (A016754). 3
1, 841, 755161, 678133681, 608963290321, 546848356574521, 491069215240629481, 440979608437728699361, 395999197307865131396641, 355606838202854450265484201, 319334544706965988473273415801, 286762065540017254794549261905041 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Colin Barker, Table of n, a(n) for n = 1..339

Index entries for linear recurrences with constant coefficients, signature (899,-899,1).

FORMULA

a(n) = 899*a(n-1)-899*a(n-2)+a(n-3).

G.f.: -x*(x^2-58*x+1) / ((x-1)*(x^2-898*x+1)).

EXAMPLE

841 is in the sequence because it is the 16th centered heptagonal number and the 15th centered octagonal number.

PROG

(PARI) Vec(-x*(x^2-58*x+1)/((x-1)*(x^2-898*x+1)) + O(x^100))

CROSSREFS

Cf. A016754, A069099, A253446, A253447.

Sequence in context: A133496 A253599 A121499 * A342841 A337730 A049530

Adjacent sequences:  A253511 A253512 A253513 * A253515 A253516 A253517

KEYWORD

nonn,easy

AUTHOR

Colin Barker, Jan 03 2015

STATUS

approved

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Last modified August 2 05:02 EDT 2021. Contains 346409 sequences. (Running on oeis4.)