|
| |
|
|
A134528
|
|
G.f. A(x) satisfies: 1 = Sum_{n>=0} A(x)^(n+1)*x^n/2^(n*(n-1)/2) where A(x) = Sum_{n>=0} a(n)*x^n/2^(n*(n-1)/2).
|
|
0
| |
|
|
1, -1, 3, -21, 319, -10193, 674047, -91369921, 25234490623, -14140806673665, 16031563354478591, -36691986271455923201, 169262051631703928107007, -1571807846118598776606101505, 29353752424684301883376834576383, -1101562988034649825668233119938625537
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,3
|
|
|
FORMULA
| G.f.: A(x) = (1/x)*series_reversion[x*Sum_{n>=0} x^n/2^(n*(n-1)/2)].
|
|
|
EXAMPLE
| A(x) = 1 - x + 3/2*x^2 - 21/8*x^3 + 319/64*x^4 - 10193/1024*x^5 +...
1 = A(x) + A(x)^2*x + A(x)^3*x^2/2 + A(x)^4*x^3/8 + A(x)^5*x^4/64 + ...
|
|
|
PROG
| (PARI) {a(n)=2^(n*(n+1)/2)*polcoeff((1/x)*serreverse(sum(k=1, n+1, x^k/2^(k*(k-1)/2))+O(x^(n+2))), n)}
|
|
|
CROSSREFS
| Cf. A118410.
Sequence in context: A055555 A158888 A005329 * A118410 A125054 A113085
Adjacent sequences: A134525 A134526 A134527 * A134529 A134530 A134531
|
|
|
KEYWORD
| sign
|
|
|
AUTHOR
| Paul D. Hanna (pauldhanna(AT)juno.com), Nov 23 2007
|
| |
|
|
