OFFSET
1,5
COMMENTS
An addition chain is a finite sequence of whole numbers starting with 1 in which each subsequent term is the sum of two (not necessarily distinct) earlier terms. - Glen Whitney, Nov 08 2021
LINKS
Glen Whitney, Table of n, a(n) for n = 1..18286 (Terms 1..1024 from D. W. Wilson)
Achim Flammenkamp, Compressed table of a(n) (for all n such that A003313(n) < 23, including all n < 196591)
Achim Flammenkamp, Shortest addition chains
Eric Weisstein's World of Mathematics, Addition Chain
Glen Whitney, C program to compute counts of addition chains
FORMULA
EXAMPLE
7 has a(7) = 5 shortest addition chains: (1,2,3,4,7), (1,2,3,5,7), (1,2,3,6,7), (1,2,4,5,7), (1,2,4,6,7).
CROSSREFS
KEYWORD
nonn
AUTHOR
David W. Wilson, Feb 09 2003
EXTENSIONS
More terms from Don Reble, Mar 31 2006
Name edited by Glen Whitney, Nov 08 2021
STATUS
approved