%I A048676
%S A048676 0,1,2,2,4,3,8,4,4,5,16,4,32,9,6,8,64,5,128,6,10,17,256,6,8,33,8,10,
%T A048676 512,7,1024,16,18,65,12,6,2048,129,34,8,4096,11,8192,18,8,257,16384,10,
%U A048676 16,9,66,34,32768,9,20,12,130,513,65536,8,131072,1025,12,32,36,19
%N A048676 Binary encoding of factorizations, alternative 2, a(n) = bef2(n);.
%C A048676 Gives same values as A048675 if the source sequence is square-free (A048672), 
               or there are max two prime divisors or one p with max exponent being 
               2 (A048623 and A048639).
%F A048676 a(1) = 0, a(n) = 1/4 * (2^(i1+e1) + 2^(i2+e2) + ... + 2^(iz+ez)) if n 
               = p_i1^e1*p_i2^e2*...*p_iz^ez, where p_i isi-th prime. (e.g. p1=2, 
               p2=3)
%p A048676 bef2 := proc(n) local s,d; s := 0; for d in ifactors(n)[ 2 ] do s := 
               s + (2^(nthprime(d[ 1 ])+d[ 2 ]-2)); od; RETURN(s); end; # for nthprime 
               see A048675
%Y A048676 Cf. A048675.
%Y A048676 Sequence in context: A163227 A048675 A162474 this_sequence A049287 A006799 
               A056429
%Y A048676 Adjacent sequences: A048673 A048674 A048675 this_sequence A048677 A048678 
               A048679
%K A048676 nonn
%O A048676 1,3
%A A048676 Antti Karttunen, Jul 14 1999