A258443 9-gonal numbers (A001106) that are the sum of eleven consecutive 9-gonal numbers.

10039491, 9002622519, 632913667646139, 567557703066557511, 39901154831776816303176, 35780879673931397997716604, 2515512364950294599811639195654, 2255755394249701567388335466918226, 158586950299955622830941025383070794461

Offset: 1

Author

Colin Barker, May 30 2015

Keywords

• nonn
• easy

Examples

			10039491 is in the sequence because A001106(1694) = 10039491 = 894861 + 898404 + 901954 + 905511 + 909075 + 912646 + 916224 + 919809 + 923401 + 927000 + 930606 = A001106(506) + ... + A001106(516).
		

Links

• Colin Barker, Table of n, a(n) for n = 1..255
• Index entries for linear recurrences with constant coefficients, signature (1,63043598,-63043598,-1,1).

Crossrefs

Cf. A001106, A258441, A258442, A258444.

Programs

Mathematica

LinearRecurrence[{1,63043598,-63043598,-1,1},{10039491,9002622519,632913667646139,567557703066557511,39901154831776816303176},10] (* Harvey P. Dale, Jan 10 2019 *)

PARI

Vec(-99*x*(4*x^4+572*x^3-211815202*x^2+90834172*x+101409) / ((x-1)*(x^2-7940*x+1)*(x^2+7940*x+1)) + O(x^20))

Formula

a(n) = a(n-1) + 63043598*a(n-2) - 63043598*a(n-3) - a(n-4) + a(n-5).

G.f.: -99*x*(4*x^4+572*x^3-211815202*x^2+90834172*x+101409) / ((x-1)*(x^2-7940*x+1)*(x^2+7940*x+1)).