

A100729


Period of the first difference of Ulam 1additive sequence U(2,2n+1).


6



32, 26, 444, 1628, 5906, 80, 126960, 380882, 2097152, 1047588, 148814, 8951040, 5406720, 242, 127842440, 11419626400, 12885001946, 160159528116, 687195466408, 6390911336402, 11728121233408, 20104735604736
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OFFSET

2,1


COMMENTS

It was proved by Akeran that a(2^k1) = 3^(k+1)  1.
Note that a(n)=2^(2n+1) as soon as A100730(n)=2^(2n+3)2, that happens for n=(m2)/2 with m>=6 being an even element of A073639.


LINKS

Max Alekseyev, Table of n, a(n) for n = 2..31
M. Akeran, On some 1additive sequences
J. Cassaigne and S. R. Finch, A class of 1additive sequences and additive recurrences
S. R. Finch, Patterns in 1additive sequences, Experimental Mathematics 1 (1992), 5763.


EXAMPLE

For k=2, we have a(3)=3^31=26.


CROSSREFS

Cf. A100730 for the fundamental difference, A001857 for U(2, 3), A007300 for U(2, 5), A003668 for U(2, 7).
Cf. also A006844.
Sequence in context: A070627 A028697 A161885 * A070728 A070619 A070626
Adjacent sequences: A100726 A100727 A100728 * A100730 A100731 A100732


KEYWORD

nonn


AUTHOR

Ralf Stephan, Dec 03 2004


EXTENSIONS

a(3) corrected from 25 to 26 by Hugo van der Sanden and Bertram Felgenhauer (inte(AT)gmx.de), Nov 11 2007
More terms from Balakrishnan V (balaji.iitm1(AT)gmail.com), Nov 15 2007
a(21..31) and bfile from Max Alekseyev, Dec 01 2007


STATUS

approved



