A145227 - OEIS

A145227

a(n) = denominator of constant lambda(n) involved in a recurrence for the Atkin polynomials A_k(j).

1, 1, 1, 1, 5, 5, 1, 2, 6, 3, 11, 11, 13, 91, 35, 20, 68, 51, 57, 19, 1, 11, 253, 46, 50, 325, 117, 63, 203, 29, 31, 248, 88, 187, 85, 15, 111, 703, 247, 26, 82, 287, 301, 473, 165, 345, 1081, 188, 28, 35, 85, 221, 689, 477, 495, 770, 266, 551, 1711, 59, 61, 1891, 93, 48, 1040, 715

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OFFSET

1,5

LINKS

Table of n, a(n) for n=1..66.

M. Kaneko and D. Zagier, Supersingular j-invariants, hypergeometric series and Atkin's orthogonal polynomials, pp. 97-126 of D. A. Buell and J. T. Teitelbaum, eds., Computational Perspectives on Number Theory, Amer. Math. Soc., 1998

FORMULA

For formula see Maple code.

EXAMPLE

720, 546, 374, 475, 2001/5, 2294/5, 410, 903/2, 2491/6, 1342/3, 4602/11, 4891/11, ...

MAPLE

lambda:=proc(n) if n=1 then 720 else 12*(6+(-1)^n/(n-1))*(6+(-1)^n/n); fi; end;

CROSSREFS

Cf. A145226.

Sequence in context: A174119 A156696 A232651 * A236555 A282969 A046095

Adjacent sequences: A145224 A145225 A145226 * A145228 A145229 A145230

KEYWORD

nonn,frac

AUTHOR

N. J. A. Sloane, Feb 28 2009

STATUS

approved