A165886 - OEIS

%I #12 Dec 19 2018 18:54:17

%S 1,6,1,60,1,42,1,120,1,66,1,5460,1,6,1,4080,1,798,1,660,1,138,1,10920,

%T 1,6,1,1740,1,14322,1,8160,1,6,1,3838380,1,6,1,54120,1,1806,1,1380,1,

%U 282,1,371280,1,66,1,3180,1,798,1,3480,1,354,1,113573460,1,6,1,16320,1,64722,1,60,1,4686,1,560403480,1,6

%N a(n) = A165641(n+1)/A165641(n).

%C Conjecture: a(n)/A141459(n+1) = A006519(n+1).

%C The conjecture is correct at least up to n<=2000. - _R. J. Mathar_, Jul 04 2011

%H Antti Karttunen, <a href="/A165886/b165886.txt">Table of n, a(n) for n = 0..16384</a>

%p A001316 := proc(n) 2^A000120(n) ;end proc:

%p A165641 := proc(n) A091137(n)/A001316(n) ;end proc:

%p A165886 := proc(n) A165641(n+1)/A165641(n) ;end proc:

%p seq(A165886(n),n=0..60) ; # _R. J. Mathar_, Jul 04 2011

%o (PARI)

%o A001316(n) = 2^hammingweight(n);

%o A091137(n) = { my(r=1); forprime(p=2, n+1, r*=p^(n\(p-1))); (r); }; \\ From A091137

%o A165641(n) = (A091137(n)/A001316(n));

%o A165886(n) = (A165641(n+1)/A165641(n)); \\ _Antti Karttunen_, Dec 19 2018, after Maple-program

%K nonn

%O 0,2

%A _Paul Curtz_, Sep 29 2009

%E More terms from _Antti Karttunen_, Dec 19 2018