A258130 Octagonal numbers (A000567) that are the sum of ten consecutive octagonal numbers.

1045, 1325345, 1910970885, 2755618515265, 3973599987865685, 5729928426883626945, 8262552817966202013445, 11914595433578836419585185, 17180838352667864150839647765, 24774756989951626526674352316385, 35725182398671892783600265200403845

Offset: 1

Author

Colin Barker, May 21 2015

Keywords

• nonn
• easy

Examples

			1045 is in the sequence because Oct(19) = 1045 = 1+8+21+40+65+96+133+176+225+280 = Oct(1) + ... + Oct(10).
		

Links

• Colin Barker, Table of n, a(n) for n = 1..316
• Index entries for linear recurrences with constant coefficients, signature (1443,-1443,1).

Crossrefs

Cf. A000567, A258128, A258129, A258131, A258132.

Programs

Mathematica

CoefficientList[Series[-95 x (63 x^2 - 1922 x + 11)/((x - 1) (x^2 - 1442 x + 1)), {x, 0, 50}], x] (* G. C. Greubel, Oct 18 2017 *)
LinearRecurrence[{1443,-1443,1},{1045,1325345,1910970885},20] (* Harvey P. Dale, Jul 25 2019 *)

PARI

Vec(-95*x*(63*x^2-1922*x+11)/((x-1)*(x^2-1442*x+1)) + O('x^20))

Formula

G.f.: -95*x*(63*x^2 - 1922*x + 11)/((x - 1)*(x^2 - 1442*x + 1)).