OFFSET
1,2
COMMENTS
In other words, a(1)=1 and then any term is a sum of two earliest possible previous terms (not necessarily distinct), given that each term must be used in summation no more than three times. So a(2)=1+1 (thus 1 gets used twice), a(3)=1+2 (thus 1 gets used for the third and final time, then 2 steps in), and so on. - Ivan Neretin, Jul 09 2015
LINKS
Joseph Myers, Table of n, a(n) for n = 1..1000
2011/12 British Mathematical Olympiad Round 2, Problem 2.
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Joseph Myers, Jan 29 2012
STATUS
approved