A246705 - OEIS

%I #10 Nov 18 2014 03:25:10

%S 1,3,4,6,8,10,11,13,15,17,19,21,22,24,26,28,30,32,34,36,37,39,41,43,

%T 45,47,49,51,53,55,56,58,60,62,64,66,68,70,72,74,76,78,79,81,83,85,87,

%U 89,91,93,95,97,99,101,103,105,106,108,110,112,114,116,118

%N Position of first n in A246694 (read as sequence with offset changed to 1); complement of A246706.

%e A246694 begins with 1, 1, 2, 3, 2, 4, 3, 5, 4, 6, 7, 5, 8, 6, 9, 7, so that, for a(n) = position of first n and b(n) = position of last n, we have a = (1,3,4,6,8,10,...) and b = (2,5,7,9,12,...).

%e Note, however, that A246694 has offset 0, so the values here are off by 1 from the positions as given by the indices (b-file or list) in that sequence. - _M. F. Hasler_, Nov 17 2014

%t z = 25; t[0, 0] = 1; t[1, 0] = 1; t[1, 1] = 2;

%t t[n_, 0] := If[OddQ[n], t[n - 1, n - 2] + 1, t[n - 1, n - 1] + 1];

%t t[n_, 1] := If[OddQ[n], t[n - 1, n - 1] + 1, t[n - 1, n - 2] + 1];

%t t[n_, k_] := t[n, k - 2] + 1;

%t u = Flatten[Table[t[n, k], {n, 0, z}, {k, 0, n}]]; (*A246694*)

%t w[n_] := Flatten[Position[u, n]]; A246705 = Table[First[w[n]], {n, 1, 3*z}]

%Y Cf. A246694, A246695, A246706.

%K nonn,easy

%O 1,2

%A _Clark Kimberling_, Sep 02 2014