This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A061389 #13 Aug 30 2019 04:17:10 %S A061389 1,2,2,2,2,4,2,3,2,4,2,4,2,4,4,3,2,4,2,4,4,4,2,6,2,4,3,4,2,8,2,5,4,4, %T A061389 4,4,2,4,4,6,2,8,2,4,4,4,2,6,2,4,4,4,2,6,4,6,4,4,2,8,2,4,4,3,4,8,2,4, %U A061389 4,8,2,6,2,4,4,4,4,8,2,6,3,4,2,8,4,4,4,6,2,8,4,4,4,4,4,10,2,4,4,4,2,8,2,6 %N A061389 Number of (1+phi)-divisors of n. %C A061389 d is called a (1+phi)-divisor of a number n with prime factorization n = Product p(i)^r(i) if d|n and d = Product p(i)^s(i), where s(i)=0 or GCD(s(i),r(i))=1. %C A061389 a(n) is odd iff n is a 3-full number (cf. A036966). %H A061389 Reinhard Zumkeller, <a href="/A061389/b061389.txt">Table of n, a(n) for n = 1..10000</a> %F A061389 Multiplicative with a(p^e) = A000010(e)+1. %t A061389 f[p_, e_] := EulerPhi[e] + 1; a[1] = 1; a[n_] := Times @@ ( f @@@ FactorInteger[n] ); Array[a, 100] (* _Amiram Eldar_, Aug 30 2019*) %o A061389 (Haskell) %o A061389 a061389 = product . map ((+ 1) . a000010 . fromIntegral) . a124010_row %o A061389 -- _Reinhard Zumkeller_, Mar 13 2012 %Y A061389 Cf. A069915, A049419, A049599. %Y A061389 Cf. A124010, A000010. %K A061389 nonn,mult %O A061389 1,2 %A A061389 _Vladeta Jovovic_, Apr 29 2001