login
The OEIS is supported by
the many generous donors to the OEIS Foundation
.
Hints
(Greetings from
The On-Line Encyclopedia of Integer Sequences
!)
A158097
G.f.: A(x) = exp( Sum_{n>=1} x^n/n * 2^(n^2)/(1 - 2^(n^2)*x^n) ).
2
1, 2, 14, 204, 16982, 6746636, 11467009772, 80444425963128, 2306004014991374374, 268654794950955551450892, 126765597355485863873077402788, 241678070949320869650125781001909864
(
list
;
graph
;
refs
;
listen
;
history
;
text
;
internal format
)
OFFSET
0,2
COMMENTS
Compare to g.f. of the partition numbers
A000041
:
exp( Sum_{n>=1} x^n/(1 - x^n)/n ) = 1 + x + 2*x^2 + 3*x^3 + 5*x^4 +...
LINKS
Table of n, a(n) for n=0..11.
FORMULA
G.f.: exp( Sum_{n>=1} x^n/n * Sum_{d|n} 2^(n*d) * n/d ).
EXAMPLE
G.f.: A(x) = 1 + 2*x + 14*x^2 + 204*x^3 + 16982*x^4 + 6746636*x^5 +...
log(A(x)) = 2*x + 24*x^2/2 + 536*x^3/3 + 66112*x^4/4 + 33554592*x^5/5 +...
log(A(x)) = 2*x/(1-2*x) + 2^4*x^2/(1-2^4*x^2)/2 + 2^9*x^3/(1-2^9*x^3)/3 +...
PROG
(PARI) {a(n)=if(n==0, 1, polcoeff(exp(sum(k=1, n, (2^k*x)^k/(1-(2^k*x)^k +x*O(x^n))/k)), n))}
for(n=0, 15, print1(a(n), ", "))
(PARI) {a(n) = polcoeff( exp( sum(m=1, n, x^m/m * sumdiv(m, d, 2^(m*d) * m/d) ) +x*O(x^n)), n)}
for(n=0, 15, print1(a(n), ", ")) \\
Paul D. Hanna
, Sep 30 2015
CROSSREFS
Cf.
A158096
,
A155200
.
Sequence in context:
A262008
A054652
A122647
*
A262003
A271847
A136550
Adjacent sequences:
A158094
A158095
A158096
*
A158098
A158099
A158100
KEYWORD
nonn
AUTHOR
Paul D. Hanna
, Mar 26 2009
STATUS
approved
Lookup
|
Welcome
|
Wiki
|
Register
|
Music
|
Plot 2
|
Demos
|
Index
|
Browse
|
More
|
WebCam
Contribute new seq. or comment
|
Format
|
Style Sheet
|
Transforms
|
Superseeker
|
Recents
The OEIS Community
| Maintained by
The OEIS Foundation Inc.
License Agreements, Terms of Use, Privacy Policy.
.
Last modified May 5 22:20 EDT 2024. Contains 372290 sequences. (Running on oeis4.)