A319700 - OEIS

%I #6 Nov 22 2018 18:16:23

%S 0,0,1,1,1,1,1,2,2,1,1,4,1,1,4,4,1,3,1,6,6,1,1,8,3,1,4,8,1,7,1,8,8,1,

%T 7,12,1,1,12,12,1,9,1,12,8,1,1,16,5,5,14,14,1,9,9,16,18,1,1,22,1,1,12,

%U 16,13,13,1,18,20,11,1,24,1,1,12,20,11,15,1,24,8,1,1,30,15,1,24,24,1,21,15,24,30,1,19,32,1,7,16,30,1,19,1,28,22

%N a(n) = A051953(A252463(n)).

%H Antti Karttunen, <a href="/A319700/b319700.txt">Table of n, a(n) for n = 1..16384</a>

%F a(n) = A051953(A252463(n)).

%o (PARI)

%o A051953(n) = (n - eulerphi(n));

%o A064989(n) = {my(f); f = factor(n); if((n>1 && f[1,1]==2), f[1,2] = 0); for (i=1, #f~, f[i,1] = precprime(f[i,1]-1)); factorback(f)};

%o A252463(n) = if(!(n%2),n/2,A064989(n));

%o A319700(n) = A051953(A252463(n));

%Y Cf. A051953, A252463.

%Y Cf. also A319699, A319703, A319989, A320107, A320111.

%K nonn

%O 1,8

%A _Antti Karttunen_, Nov 22 2018