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”).
%I #9 Jul 23 2013 13:24:33
%S 3,6,18,13,42,38,93,18,56,102,186,74,324,198,342,48,540,110,546,272,
%T 756,588,972,180,312,678,126,528,1266,972,1596,84,1980,1260,1842,256,
%U 2484,1842,2286,402,2613,2124,3534,1440,1281,2220,4536,307,660,672
%N Sum of divisors of n*rad(n)+1, where rad=A007947 (squarefree kernel).
%C a(n)=A000203(A078310(n)).
%H Reinhard Zumkeller, <a href="/A078318/b078318.txt">Table of n, a(n) for n = 1..10000</a>
%o (PARI) rad(n)=vecprod(factor(n)[,1])
%o a(n)=sigma(n*rad(n)+1) \\ _Charles R Greathouse IV_, Jul 09 2013
%o (Haskell)
%o a078318 = a000203 . a078310 -- _Reinhard Zumkeller_, Jul 23 2013
%Y Cf. A078317, A078319, A078320.
%K nonn
%O 1,1
%A _Reinhard Zumkeller_, Nov 23 2002