A335158 Define b(n) by 1/sm(w) = Sum_{n >= 0} b(3*n-1)*w^(3*n-1), where sm(w) is the elliptic function defined in A104133; a(n) = denominator of b(3*n-1).

1, 6, 252, 4536, 2476656, 3714984, 35574686784, 15246294336, 582713369521920, 1123804355506560, 2048470579217357568, 35116638500868986880, 283061106066827553906954240, 4665842407694959679784960, 1533625072670071687067878072320, 394360732972304148103168647168

Offset

0,2

References

Oscar S. Adams, Elliptic Functions Applied to Conformal World Maps, Special Publication No. 112 of the U.S. Coast and Geodetic Survey, 1925. See pp. 3-4.

Links

Table of n, a(n) for n=0..15.

Example

1/sm(w) = w^(-1) + (1/6)*w^2 - (1/252)*w^5 - (1/4536)*w^8 + (11/2476656)*w^11 + (1/3714984)*w^14 - (193/35574686784)*w^17 - (5/15246294336)*w^20 + (3851/582713369521920)*w^23 + (449/1123804355506560)*w^26 - ...

Prog

(PARI) aden(nn) = my(A = O(x)); for(i=0, nn, A = intformal( (1 - intformal(A^2))^2) ); my(v=Vec(1/A)); apply(x->denominator(x), vector(#v\3, k, v[3*k-2]));

Crossrefs

Cf. A104133 (sm), A104134 (cm), A335157 (numerators).

See also A335180, A335181.

Sequence in context: A229475 A281054 A056238 * A221822 A361186 A184424

Adjacent sequences: A335155 A335156 A335157 * A335159 A335160 A335161

Keyword

nonn,frac

Author

Michel Marcus and N. J. A. Sloane, Jun 08 2020

Status

approved