A322991 - OEIS

%I #7 Jan 02 2019 11:55:10

%S 1,3,4,5,7,12,8,9,11,15,13,20,16,21,28,17,19,24,23,35,36,33,25,44,27,

%T 39,29,40,31,60,32,37,52,48,56,45,41,51,68,63,43,84,47,55,77,57,49,76,

%U 53,69,92,65,59,75,91,72,100,87,61,140,64,93,88,67,112,132,71,80,108,105,73,99,79,96,116,85,104,156,81,119,83,111,89

%N a(n) = A289272(2*A289271(n)).

%H Antti Karttunen, <a href="/A322991/b322991.txt">Table of n, a(n) for n = 1..16384</a>

%F a(n) = A289272(2*A289271(n)).

%o (PARI)

%o A289271(n) = { my(v=0,i=0,x=1); for(d=2,oo,if(n==1, return(v)); if(1==gcd(x,d)&&1==omega(d), if(!(n%d)&&1==gcd(d,n/d), v += 2^i; n /= d; x *= d); i++)); }; \\ After _Rémy Sigrist_'s program for A289271.

%o A289272(n) = { my(m=1, pp=1); while(n>0, pp++; while(!isprimepower(pp)||(gcd(pp,m)>1), pp++); if(n%2, m *= pp); n >>=1); (m); };

%o A322991(n) = A289272(2*A289271(n));

%Y Permutation of A042965 (apart from zero).

%Y Cf. A289271, A289272, A322990, A322992.

%Y Cf. also A003963, A300841.

%K nonn

%O 1,2

%A _Antti Karttunen_, Jan 01 2019