OFFSET
1,2
COMMENTS
Could arithmetic tribonacci mean (T(0)+...+T(n-1)) / n be an integer?
The arithmetic means are integers for the first 1, 2, 47, 53, 94, 103, 106 etc. tribonacci numbers. - R. J. Mathar, Aug 04 2008
FORMULA
n such that (T(0)^2+ T(1)^2+ ... + T(n-1)^2) / n is an integer. T(i) = i-th tribonacci number.
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Ctibor O. Zizka, Jul 27 2008
EXTENSIONS
Added 1 and 2 and extended from 32 on, R. J. Mathar, Aug 04 2008
STATUS
approved