The OEIS mourns the passing of
Jim Simons
and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
login
The OEIS is supported by
the many generous donors to the OEIS Foundation
.
Hints
(Greetings from
The On-Line Encyclopedia of Integer Sequences
!)
A214691
G.f.: A(x) = Sum_{n>=0} x^n * Product_{k=1..n} (2^(2*k-1) - 1) / (1 + 2^(2*k-1)*x).
1
1, 1, 5, 151, 19025, 9702751, 19851828545, 162586475783551, 5327308465523832065, 698250320576208668759551, 366082867573618138109269955585, 767730685732013278335855487355082751, 6440190236715680978727827356359771295535105
(
list
;
graph
;
refs
;
listen
;
history
;
text
;
internal format
)
OFFSET
0,3
COMMENTS
A variant of
A005014
. Equals row sums (unsigned) of triangle
A214690
.
LINKS
Table of n, a(n) for n=0..12.
FORMULA
a(n) = 2*(4^(n-1) - 1)*a(n-1) - (-1)^n for n>0 with a(0)=1.
PROG
(PARI) {a(n)=if(n==0, 1, 2*(4^(n-1)-1)*a(n-1) - (-1)^n)}
(PARI) {a(n)=local(A=x); A=sum(m=0, n, x^m*prod(j=1, m, (2^(2*j-1)-1)/(1+x*2^(2*j-1))+x*O(x^n))); polcoeff(A, n, x)}
for(n=0, 20, print1(a(n), ", "));
CROSSREFS
Cf.
A005014
(variant),
A214690
.
Sequence in context:
A332115
A262655
A075598
*
A261822
A105230
A222768
Adjacent sequences:
A214688
A214689
A214690
*
A214692
A214693
A214694
KEYWORD
nonn
AUTHOR
Paul D. Hanna
, Jul 26 2012
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 14 14:06 EDT 2024. Contains 372533 sequences. (Running on oeis4.)