%I #7 Oct 17 2014 23:19:17
%S 1,2,3,4,6,7,9,10,12,14,15,17,19,21,22,24,26,28,30,32,33,35,37,39,41,
%T 43,45,47,48,50,52,54,56,58,60,62,64,66,68,69,71,73,75,77,79,81,83,85,
%U 87,89,91,93,95,97,99,100,102,104,106,108,110,112,114,116
%N Numbers k such that A248633(k+1) = A248633(k) + 2.
%H Clark Kimberling, <a href="/A248635/b248635.txt">Table of n, a(n) for n = 1..500</a>
%e (A248633(k+1) = A248633(k)) = (2, 2, 2, 2, 1, 2, 2, 1, 2, 2, 1, 2, 1, 2, 2, 1,... ), so that A248634 = (5, 8, 11, 13, ... ) and A248635 = (1, 2, 3, 4, 6, 7, 9, 10, 12, ...).
%t z= 300; p[k_] := p[k] = Sum[(h^2/4^h), {h, 1, k}];
%t d = N[Table[20/27 - p[k], {k, 1, z/5}], 12];
%t f[n_] := f[n] = Select[Range[z], 20/27 - p[#] < 1/8^n &, 1];
%t u = Flatten[Table[f[n], {n, 1, z}]] (* A248633 *)
%t d = Differences[u]
%t Flatten[Position[d, 1]] (* A248634 *)
%t Flatten[Position[d, 2]] (* A248635 *)
%Y Cf. A248633, A248634, A248630.
%K nonn,easy
%O 1,2
%A _Clark Kimberling_, Oct 11 2014