|
%I #9 Dec 24 2019 17:30:51
%S 1,1,2,2,4,6,8,12,6,16,4,24,30,32,36,48,60,64,72,12,96,30,8,120,128,
%T 144,180,192,210,216,240,256,288,360,384,420,432,36,480,512,24,576,60,
%U 16,720,768,840,864,900,960,1024,1080,1152,210,1260,1296,1440,1536,1680,1728,1800,1920,2048,2160,2304,2310,2520,2592,72
%N If A181815(n) is odd, a(n) = A064989(A025487(n)), otherwise a(n) = A025487(n)/2.
%C If 2-adic and 3-adic valuations of A025487(n) are equal, then a(n) = A064989(A025487(n)), otherwise a(n) = A025487(n)/2.
%C Only terms of A025487 occur, and each one of them occurs exactly twice.
%H Antti Karttunen, <a href="/A329899/b329899.txt">Table of n, a(n) for n = 1..10000</a>
%F If A181815(n) is odd, a(n) = A064989(A025487(n)), otherwise a(n) = A025487(n)/2.
%F a(n) = A025487(A329904(n)).
%o (PARI)
%o A181815(n) = A329900(A025487(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 A329899(n) = if(A181815(n)%2,A064989(A025487(n)),A025487(n)/2);
%Y Cf. A025487, A064989, A181815, A329897, A329898, A329904.
%K nonn
%O 1,3
%A _Antti Karttunen_, Dec 24 2019
|
