A291757 - OEIS

%I #14 Nov 28 2018 20:58:38

%S 1,2,2,12,2,16,2,59,18,16,2,80,2,16,16,261,2,94,2,80,16,16,2,355,33,

%T 16,129,80,2,436,2,1097,16,16,16,826,2,16,16,355,2,436,2,80,94,16,2,

%U 1493,52,125,16,80,2,505,16,355,16,16,2,1832,2,16,94,4497,16,436,2,80,16,436,2,3415,2,16,125,80,16,436,2,1493,888,16,2,1832,16,16,16,355,2

%N a(n) = (1/2)*(2 + ((A003557(n)+A046523(n))^2) - A003557(n) - 3*A046523(n)).

%H Antti Karttunen, <a href="/A291757/b291757.txt">Table of n, a(n) for n = 1..16385</a>

%F a(n) = (1/2)*(2 + ((A003557(n)+A046523(n))^2) - A003557(n) - 3*A046523(n)).

%o (PARI)

%o A003557(n) = n/factorback(factor(n)[, 1]); \\ From A003557

%o A046523(n) = { my(f=vecsort(factor(n)[, 2], , 4), p); prod(i=1, #f, (p=nextprime(p+1))^f[i]); };  \\ From A046523

%o A291757(n) = (1/2)*(2 + ((A003557(n)+A046523(n))^2) - A003557(n) - 3*A046523(n));

%Y Cf. A000027, A003557, A046523, A291750, A291752, A291756, A291758, A294877 (rgs-transform), A319347.

%K nonn

%O 1,2

%A _Antti Karttunen_, Sep 10 2017

%E Name changed by _Antti Karttunen_, Nov 28 2018