login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A107958 a(n) = term at position 2^n in A107957. 1
1, 3, 11, 52, 331, 2949, 38069, 733817, 21670554, 1001901607, 73852354365, 8813580443406, 1725174170633694 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Also terms at positions 2^(n+1) - 1 of A107947, where A107947 equals the first differences of A107957.

LINKS

Table of n, a(n) for n=0..12.

FORMULA

a(n) = A107957(2^n). a(n) = A107947(2^(n+1) - 1).

PROG

(PARI) {a(n)=local(A=[1, 2]); for(i=1, n, B=vector(#A, k, polcoeff(Ser(A)/(1-x), k-1)+A[2^#binary(#A-1)]); A=concat(A, B); ); sum(k=1, 2^n, A[k])}

CROSSREFS

Cf. A107946, A107947, A107948, A107957.

Sequence in context: A054362 A129833 A321585 * A253972 A053557 A039302

Adjacent sequences:  A107955 A107956 A107957 * A107959 A107960 A107961

KEYWORD

nonn

AUTHOR

Paul D. Hanna, May 29 2005

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 26 00:32 EDT 2020. Contains 334613 sequences. (Running on oeis4.)