cp's OEIS Frontend

A324349 a(n) = A324122(A005940(1+n)), where A005940 is the Doudna sequence and A324122(n) = sigma(n) - gcd(n*d(n), sigma(n)).

%I A324349 #11 Feb 24 2019 17:52:58
%S A324349 0,2,2,6,4,0,12,14,6,16,12,24,30,36,36,30,10,16,28,36,44,48,72,48,54,
%T A324349 90,122,90,152,96,120,60,12,32,36,0,68,48,102,80,92,128,168,144,246,
%U A324349 216,120,120,132,168,222,216,336,360,402,192,396,464,600,272,780,360,362,126,16,40,52,72,80,96,150,112,84,208,264,112,366,288,312,184,164,272,360,0,568
%N A324349 a(n) = A324122(A005940(1+n)), where A005940 is the Doudna sequence and A324122(n) = sigma(n) - gcd(n*d(n), sigma(n)).
%C A324349 Zeros occur in the same positions as in A324057, and can be obtained by sorting into ascending order the terms obtained with A156552(A001599(n)), n >= 1.
%H A324349 Antti Karttunen, <a href="/A324349/b324349.txt">Table of n, a(n) for n = 0..16384</a>
%H A324349 Antti Karttunen, <a href="/A324349/a324349.txt">Data supplement: n, a(n) computed for n = 0..65537</a>
%F A324349 a(n) = A324122(A005940(1+n)).
%F A324349 a(n) = A324054(n) - A324058(n).
%F A324349 For n > 0, a(n) = A324189(A054429(n)).
%o A324349 (PARI)
%o A324349 A005940(n) = { my(p=2, t=1); n--; until(!n\=2, if((n%2), (t*=p), p=nextprime(p+1))); t }; \\ From A005940
%o A324349 A324122(n) = (sigma(n) - gcd(sigma(n),n*numdiv(n)));
%o A324349 A324349(n)  = A324122(A005940(1+n));
%Y A324349 Cf. A005940, A054429, A324054, A324057, A324058, A324189
%Y A324349 Cf. also A001599.
%K A324349 nonn
%O A324349 0,2
%A A324349 _Antti Karttunen_, Feb 24 2019