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A026045 a(n) = (d(n)-r(n))/5, where d = A026043 and r is the periodic sequence with fundamental period (0,2,3,0,0). 1
9, 13, 19, 28, 39, 53, 70, 91, 117, 147, 182, 222, 268, 321, 380, 446, 519, 600, 690, 788, 895, 1011, 1137, 1274, 1421, 1579, 1748, 1929, 2123, 2329, 2548, 2780, 3026, 3287, 3562, 3852, 4157, 4478, 4816, 5170, 5541, 5929, 6335, 6760, 7203, 7665, 8146, 8647, 9169, 9711, 10274, 10858, 11464 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..53.

Index entries for linear recurrences with constant coefficients, signature (3,-3,1,0,1,-3,3,-1).

FORMULA

a(n)=(n + 5)*(2*n^2 + 11*n + 54)/30 - (1 + ( - 1/2 - 1/10*5^(1/2))*cos(2*n*Pi/5) + (1/10*(3*(5 - 5^(1/2))^(1/2) + 2*(5 + 5^(1/2))^(1/2))*2^(1/2))*sin(2*n*Pi/5) + (1/10*5^(1/2) - 1/2)*cos(4*n*Pi/5) + (1/10*(2*(5 - 5^(1/2))^(1/2) - 3*(5 + 5^(1/2))^(1/2))*2^(1/2))*sin(4*n*Pi/5))/5 [From Richard Choulet, Dec 14 2008]

G.f. x*( 9-14*x+7*x^2+x^3-x^4-8*x^5-6*x^7+14*x^6 ) / ( (x^4+x^3+x^2+x+1)*(x-1)^4 ). - R. J. Mathar, Jun 22 2013

CROSSREFS

A152857 [From Richard Choulet, Dec 14 2008]

Sequence in context: A090415 A026283 A307287 * A304259 A124249 A137168

Adjacent sequences:  A026042 A026043 A026044 * A026046 A026047 A026048

KEYWORD

nonn

AUTHOR

Clark Kimberling

STATUS

approved

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Last modified February 18 21:20 EST 2020. Contains 332028 sequences. (Running on oeis4.)