OFFSET
1,2
FORMULA
It appears that for n>1 a(n)=( 47*5^(n-2)-3 )/4 and if 2*a(n-1)+1 < k < 2*a(n)+1, then b(k)= -a(n), if k = 2*a(n)+1 b(k)= +a(n).
Empirical g.f.: -x*(3*x^2-5*x-1) / ((x-1)*(5*x-1)). - Colin Barker, Jun 17 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
Benoit Cloitre, Aug 30 2002
STATUS
approved