|
%I #8 Jan 06 2021 17:48:30
%S 1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,1,1,1,1,1,0,1,1,1,1,1,1,1,1,0,1,1,0,1,
%T 0,1,1,1,0,1,1,0,1,1,0,1,1,1,1,1,0,1,1,1,0,1,0,1,1,0,1,1,0,1,0,0,1,1,
%U 0,0,1,1,1,1,0,1,0,0,1,1,1,1,1,0,0,1,0,1,1,0,0,1,0,1,0,1,1,1,0,1,1,0,1,1,0
%N a(n) = 1 if n is of the form of 2^i * p^j, with p an odd prime and i, j >= 0, otherwise 0.
%C a(n) = 1 if the odd part of n has no more than one distinct prime divisor, and 0 otherwise.
%H Antti Karttunen, <a href="/A340363/b340363.txt">Table of n, a(n) for n = 1..65537</a>
%H <a href="/index/Ch#char_fns">Index entries for characteristic functions</a>
%F a(n) = A010055(A000265(n)).
%F a(n) = [A005087(n) <= 1], where [ ] is the Iverson bracket, and A005087(n) = A001221(A000265(n)).
%F a(n) = A209229(n) + A340373(n).
%F For all n, a(n) <= A340372(n).
%o (PARI)
%o A000265(n) = (n>>valuation(n, 2));
%o A340363(n) = (omega(A000265(n))<=1);
%Y Cf. A000265, A001221, A005087, A010055, A209229, A340372, A340373.
%Y Characteristic function of {1} U A070776.
%K nonn
%O 1
%A _Antti Karttunen_, Jan 06 2021
|
