login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

One half the number of divisors of nonprime numbers that are 3 (mod 4).
1

%I #5 Aug 03 2016 09:02:21

%S 2,2,2,2,2,2,3,3,2,2,2,3,2,2,2,2,4,2,3,2,2,3,3,2,2,4,4,4,4,4,4,4,4,4,

%T 4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,

%U 4,4

%N One half the number of divisors of nonprime numbers that are 3 (mod 4).

%C Row length numbers of A273164.

%C With the Jan 05 2004 Jovovic comment on A078703 a(n) is also the number of divisors +1 as well as -1 (mod 4) of A091236(n). See the example section of A273164.

%F a(n) = number of divisors of A091236(n)(nonprime numbers 3 (mod 4)).

%Y Cf. A078703, A091236, A273164.

%K nonn,easy

%O 1,1

%A _Wolfdieter Lang_, Jul 29 2016