OFFSET
1,1
COMMENTS
To construct the sequence use the rule : a(1)=3, then a(a(1)+a(2)+...+a(n)+1)=2+(-1)^n and fill in any undefined place with 2.
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..8192 (computed from the b-file of A004200 provided by Harry J. Smith)
FORMULA
a(n) = (1/2) * (1+A004200(n+1)).
a(a(1)+a(2)+...+a(n)+1) = 2+(-1)^n.
EXAMPLE
Example to illustrate the comment : a(a(1)+1) = a(4) = 2+(-1)^1 = 1 and a(2), a(3) are undefined. The rule forces a(2) = a(3) = 2.
CROSSREFS
KEYWORD
nonn
AUTHOR
Benoit Cloitre, Nov 08 2003
STATUS
approved