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A079626
Let u(1)=u(2)=1, u(n)=abs(u(n-1)-3/2*u(n-2)); then a(n) is the exponent of 2 in denominator of u(n).
0
0, 0, 1, 0, 2, 2, 3, 0, 4, 4, 5, 4, 6, 6, 7, 4, 8, 8, 9, 8, 10, 10, 11, 10, 12, 12, 13, 9, 14, 14, 15, 14, 1, 6, 16, 17, 16, 18, 18, 19, 17, 20, 20, 21, 19, 22, 22, 23, 21, 24, 24, 25, 23, 26, 26, 27, 26, 28, 28, 29, 27, 30, 30, 31, 30, 32, 32, 33, 31, 34, 34, 35, 34, 36, 36, 37, 35
OFFSET
1,5
COMMENTS
Does u(n) diverge to infinity?
FORMULA
a(n)<n/2, a(2n+1)=n+1.
PROG
(PARI) a=b=1; for(n=3, 100, c=abs(b-3*a/2); a=b; b=c; print1(valuation(denominator(c), 2), ", "))
CROSSREFS
Sequence in context: A137345 A060755 A104594 * A257697 A088864 A330925
KEYWORD
nonn
AUTHOR
Benoit Cloitre, Jan 30 2003
STATUS
approved