OFFSET
1,1
LINKS
Hugo Pfoertner, Table of n, a(n) for n = 1..10000
EXAMPLE
a(3)=427 because both 427 and 1281=3*427 have associated shortest addition chains of length 12: [1,2,4,8,16,17,34,68,136,137,145,290,427] and [1,2,4,5,10,20,40,80,160,320,640,1280]. This is the third occurrence of such a pair. The first two are (171,513) and (342,1026).
CROSSREFS
KEYWORD
nonn
AUTHOR
Hugo Pfoertner, Mar 07 2006
STATUS
approved