A135612 - OEIS

%I #2 Mar 30 2012 17:33:53

%S 1,10,1000,100000,100000000000,1000000000000000,100000000000000000,

%T 100000000000000000000000000000,

%U 100000000000000000000000000000000000000000000000000000000000

%N Even superperfect numbers divided by 2, written in base 2.

%C Also, concatenation of "1" and A000043(n)-2 digits "0".

%C The number of divisors of a(n) is equal to the number of its digits. This number is equal to A090748(n)=A000043(n)-1.

%F a(n)=A134708(n) written in base 2.

%e a(3)=1000 because A134708(n)=8 and 8 written in base 2 is 1000.

%Y Even superperfect numbers divided by 2: A134708. Cf. A000043, A019279, A090748, A135651, A135656.

%K base,nonn

%O 1,2

%A _Omar E. Pol_, Mar 01 2008