OFFSET
1,3
COMMENTS
The absolute value is relevant only when a(n) = 0, in which case a(n+1) = gcd(a(n), 3n+2) = 3n+2.
It is conjectured that a(n) = 0 implies that 3n+2 = a(n+1) is prime, for all n > 2, cf. A186255. (This is the sequence {u(n)} mentioned there.)
PROG
(PARI) print1(a=1); for(n=1, 199, print1(", ", a=abs(a-gcd(a, 3*n+2))))
CROSSREFS
KEYWORD
nonn
AUTHOR
M. F. Hasler, Aug 14 2015
STATUS
approved