cp's OEIS Frontend

A299242 Ranks of {2,3}-power towers in which #2's < #3's; see Comments.

%I A299242 #14 Aug 07 2024 15:12:24
%S A299242 2,7,11,12,15,16,24,26,32,33,34,38,42,46,48,49,50,52,53,54,64,65,66,
%T A299242 67,68,69,70,78,86,94,98,100,101,102,106,108,109,110,126,130,132,133,
%U A299242 134,136,137,138,139,140,141,142,150,154,156,157,158,166,170,172
%N A299242 Ranks of {2,3}-power towers in which #2's < #3's; see Comments.
%C A299242 Suppose that S is a set of real numbers. An S-power-tower, t, is a number t = x(1)^x(2)^...^x(k), where k >= 1 and x(i) is in S for i = 1..k. We represent t by (x(1), x(2), ..., x(k)), which for k > 1 is defined as (x(1), (x(2), ..., x(k))); (2,3,2) means 2^9. The number k is the *height* of t. If every element of S exceeds 1 and all the power towers are ranked in increasing order, the position of each in the resulting sequence is its *rank*. See A299229 for a guide to related sequences.
%C A299242 This sequence together with A299240 and A299241 partition the positive integers.
%H A299242 Clark Kimberling, <a href="/A299242/b299242.txt">Table of n, a(n) for n = 1..1000</a>
%e A299242 The first six terms are the ranks of these towers: t(2) = (3), t(7) = (3,3), t(11) = (3,2,3), t(12) = (3,3,2), t(15) = (2,3,3), t(16) = (3,3,3).
%t A299242 t[1] = {2}; t[2] = {3}; t[3] = {2, 2}; t[4] = {2, 3}; t[5] = {3, 2};
%t A299242 t[6] = {2, 2, 2}; t[7] = {3, 3}; t[8] = {3, 2, 2}; t[9] = {2, 2, 3};
%t A299242 t[10] = {2, 3, 2}; t[11] = {3, 2, 3}; t[12] = {3, 3, 2};
%t A299242 z = 190; g[k_] := If[EvenQ[k], {2}, {3}]; f = 6;
%t A299242 While[f < 13, n = f; While[n < z, p = 1;
%t A299242   While[p < 12, m = 2 n + 1; v = t[n]; k = 0;
%t A299242     While[k < 2^p, t[m + k] = Join[g[k], t[n + Floor[k/2]]]; k = k + 1];
%t A299242    p = p + 1; n = m]]; f = f + 1]
%t A299242 Select[Range[1000], Count[t[#], 2] > Count[t[#], 3] &];   (* A299240 *)
%t A299242 Select[Range[1000], Count[t[#], 2] == Count[t[#], 3] &];  (* A299241 *)
%t A299242 Select[Range[1000], Count[t[#], 2] < Count[t[#], 3] &];  (* this sequence *)
%Y A299242 Cf. A299229, A299240, A299241.
%K A299242 nonn,easy
%O A299242 1,1
%A A299242 _Clark Kimberling_, Feb 07 2018