OFFSET
0,2
COMMENTS
a(n) is the number of solutions to the Diophantine equation 2*x^2 - (9*n+1)*x + 9*n^2 = 1 where valid solutions are restricted to powers of 4. - Hieronymus Fischer, May 17 2007
LINKS
Antti Karttunen, Table of n, a(n) for n = 0..87381
FORMULA
EXAMPLE
a(1)=2 since J(1)=J(2)=1.
PROG
(PARI)
A147612aux(n, i) = if(!(n%2), n, A147612aux((n+i)/2, -i));
A147612(n) = 0^(A147612aux(n, 1)*A147612aux(n, -1));
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Paul Barry, Apr 01 2005
STATUS
approved