A092510 - OEIS

%I #13 Oct 20 2017 14:26:39

%S 2,1,1,0,1,0,1,0,0,0,1,0,1,0,0,0,1,1,1,0,0,0,1,1,0,0,3,0,1,1,1,2,0,0,

%T 0,2,1,0,0,2,1,1,1,0,3,0,1,3,0,3,0,0,1,4,0,2,0,0,1,4,1,0,3,4,0,1,1,0,

%U 0,3,1,5,1,0,7,0,0,1,1,5,6,0,1,5,0,0,0,2,1,6,0,0,0,0,0,7,1,5,3,6,1,1,1,2,7,0

%N Difference between smallest semiperimeter (see A063655) and its integer log (see A001414).

%H Antti Karttunen, <a href="/A092510/b092510.txt">Table of n, a(n) for n = 1..16384</a>

%F a(n) = A063655(n) - A001414(n).

%e If p is prime a(p)=1 because A063655(p) = p+1 and A001414(p) = p.

%o (PARI)

%o A001414(n) = { my(f=factor(n)); sum(k=1, matsize(f)[1], f[k, 1]*f[k, 2]); }; \\ From A001414.

%o A063655(n) = { my(c=1); fordiv(n,d,if((d*d)>=n,if((d*d)==n,return(2*d),return(c+d))); c=d); (0); };

%o A092510(n) = (A063655(n)-A001414(n)); \\ _Antti Karttunen_, Oct 20 2017

%Y Cf. A063655 and A001414.

%K nonn

%O 1,1

%A _Carlos Alves_, Dec 31 2004

%E Offset corrected and missing term a(1) = 2 prepended by _Antti Karttunen_, Oct 20 2017