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A188039 Positions of 0 in A188038; complement of A188040.

%I A188039 #13 Jun 25 2025 04:06:32
%S A188039 2,7,12,19,24,31,36,41,48,53,60,65,70,77,82,89,94,101,106,111,118,123,
%T A188039 130,135,140,147,152,159,164,171,176,181,188,193,200,205,210,217,222,
%U A188039 229,234,239,246,251,258,263,270,275,280,287,292,299,304,309,316,321,328,333,340,345,350,357,362,369,374,379,386,391,398,403,408,415,420
%N A188039 Positions of 0 in A188038; complement of A188040.
%C A188039 See A188014.
%C A188039 There is (conjecturally) a connection a(1+n) = f(n) where f(n) = 3*n +2 +2*floor(n*sqrt 2) is defined in A120861. Tested numerically up to n=40000. - _R. J. Mathar_, Jul 22 2020
%H A188039 G. C. Greubel, <a href="/A188039/b188039.txt">Table of n, a(n) for n = 1..10000</a>
%p A188039 A188038 := proc(n)
%p A188039     if n = 1 then
%p A188039         1;
%p A188039     else
%p A188039         floor(n*sqrt(2))-floor((n-2)*sqrt(2))-2 ;
%p A188039     end if;
%p A188039 end proc:
%p A188039 isA188039 := proc(n)
%p A188039     if A188038(n) = 0 then
%p A188039         true;
%p A188039     else
%p A188039         false;
%p A188039     end if;
%p A188039 end proc:
%p A188039 A188039 := proc(n)
%p A188039     option remember;
%p A188039     if n = 1 then
%p A188039         2;
%p A188039     else
%p A188039         for a from procname(n-1)+1 do
%p A188039             if isA188039(a) then
%p A188039                 return a;
%p A188039             end if;
%p A188039         end do:
%p A188039     end if;
%p A188039 end proc: # _R. J. Mathar_, Jul 22 2020
%t A188039 (* See A188038. *)
%Y A188039 Cf. A188038, A188014, A188040.
%K A188039 nonn
%O A188039 1,1
%A A188039 _Clark Kimberling_, Mar 19 2011