A218540 - OEIS

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A218540

Reduced third-order Patalan numbers.

1, 1, 1, 5, 10, 66, 154, 1122, 2805, 21505, 55913, 442221, 1179256, 9524760, 25852920, 211993944, 582983346, 4835332458, 13431479050, 112400272050, 314720761740, 2652646420380, 7475639911980, 63380425340700, 179577871798650, 1530003467724498

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OFFSET

0,4

COMMENTS

Obtained by removing powers of 3 in a systematic manner from the Patalan numbers A025748.

LINKS

Table of n, a(n) for n=0..25.

R. J. Mathar, Series expansion of generalized Fresnel integrals, arXiv:1211.3963, (4.19)

FORMULA

a(n) = A025748(n)/A108411(n).

D-finite with recurrence n*(n+2)*(n-1)*a(n) + (n-1)*(n-2)*(n+4)*a(n-1) - 3*(3*n-4)*(3*n-7)*(n+2)*a(n-2) - 3*(3*n-10)*(n+4)*(3*n-7)*a(n-3) = 0, n >= 4.

MAPLE

A218540 := proc(n)

option remember;

if n <=2 then

elif n = 3 then

5 ;

else

(n-1)*(n-2)*(n+4)*procname(n-1)-3*(3*n-4)*(3*n-7)*(n+2)*procname(n-2)-3*(3*n-10)*(n+4)*(3*n-7)*procname(n-3) ;

-%/n/(n+2)/(n-1) ;

end if;

end proc:

CROSSREFS

Sequence in context: A062848 A054884 A061518 * A174937 A180851 A056316

Adjacent sequences: A218537 A218538 A218539 * A218541 A218542 A218543

KEYWORD

nonn,easy

AUTHOR

R. J. Mathar, Nov 01 2012

STATUS

approved