1,3

a(n) = 1 if n = 2^a*5^b where a or b can be 0 or any posiive integer. a(9n+3)=a(9n+6)= 3, a(9n)= 9. Conjecture: a(k) = 2 if k is odd and takes any form other than mentioned above. and the multiple is of the form 10^r +1. a(k) = 3 if k is even and takes any form other than mentioned above.

Cf. A077194, A077195.

Sequence in context: A093415 A106749 A140216 this_sequence A023142 A033989 A099545

Adjacent sequences: A077193 A077194 A077195 this_sequence A077197 A077198 A077199

base,nonn

Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Nov 01 2002

More terms from Sascha Kurz (sascha.kurz(AT)uni-bayreuth.de), Feb 10 2003