A282843 - OEIS

A282843

Numbers n for which id(n) = id(n + id(n)), where id(n) = A037445(n) is the number of infinitary divisors of n.

%I #6 Feb 22 2017 15:57:40

%S 2,3,5,6,7,8,9,10,11,14,17,18,22,23,28,29,32,34,35,41,44,46,47,48,51,

%T 58,59,64,65,70,71,76,79,81,82,87,88,91,94,95,96,101,102,107,111,112,

%U 115,118,119,125,128,129,130,132,137,141,142,143,144,149,152,155

%N Numbers n for which id(n) = id(n + id(n)), where id(n) = A037445(n) is the number of infinitary divisors of n.

%C The infinitary analog of A175304. The sequence contains smaller of pairs(p,q) of terms of A050376 if q-p=2 (Fermi-Dirac twin primes). Unlike A175304, this sequence contains some squares (64,81,144,...).

%H Charles R Greathouse IV, <a href="/A282843/b282843.txt">Table of n, a(n) for n = 1..10000</a>

%o (PARI) id(n)=2^vecsum(apply(hammingweight, factor(n)[,2]))

%o is(n)=my(i=id(n)); id(n+i)==i \\ _Charles R Greathouse IV_, Feb 22 2017

%Y Cf. A037445, A050376, A175304.

%K nonn

%O 1,1

%A _Vladimir Shevelev_, Feb 22 2017

%E More term from _Peter J. C. Moses_, Feb 22 2017