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A130489 a(n) = Sum_{k=0..n} (k mod 11) (Partial sums of A010880). 4
0, 1, 3, 6, 10, 15, 21, 28, 36, 45, 55, 55, 56, 58, 61, 65, 70, 76, 83, 91, 100, 110, 110, 111, 113, 116, 120, 125, 131, 138, 146, 155, 165, 165, 166, 168, 171, 175, 180, 186, 193, 201, 210, 220, 220, 221, 223, 226, 230, 235, 241, 248, 256, 265, 275, 275, 276 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

Let A be the Hessenberg n X n matrix defined by A[1,j] = j mod 11, A[i,i]:=1, A[i,i-1]=-1. Then, for n >= 1, a(n)=det(A). [Milan Janjic, Jan 24 2010]

LINKS

Shawn A. Broyles, Table of n, a(n) for n = 0..1000

FORMULA

a(n) = 55*floor(n/11) + A010880(n)*(A010880(n) + 1)/2.

G.f.: (Sum_{k=1..10} k*x^k)/((1-x^11)(1-x)).

G.f.: x(10x^11-11x^10+1)/((1-x^11)(1-x)^3).

PROG

(PARI) a(n) = sum(k=0, n, k % 11); \\ Michel Marcus, Apr 28 2018

CROSSREFS

Cf. A010872, A010873, A010874, A010875, A010876, A010877, A010878, A010879, A130481, A130482, A130483, A130484, A130485, A130486, A130487, A130488.

Sequence in context: A071817 A033442 A105335 * A211024 A261422 A262544

Adjacent sequences:  A130486 A130487 A130488 * A130490 A130491 A130492

KEYWORD

nonn

AUTHOR

Hieronymus Fischer, May 31 2007

STATUS

approved

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Last modified March 18 13:47 EDT 2019. Contains 321289 sequences. (Running on oeis4.)