A248637 Numbers k such that A248636(k+1) = A248636(k) + 1.

2, 4, 7, 8, 10, 12, 14, 15, 17, 19, 20, 22, 23, 25, 26, 28, 29, 31, 32, 34, 35, 37, 38, 40, 41, 43, 44, 46, 47, 48, 50, 51, 53, 54, 56, 57, 59, 60, 61, 63, 64, 66, 67, 69, 70, 71, 73, 74, 76, 77, 78, 80, 81, 83, 84, 86, 87, 88, 90, 91, 93, 94, 95, 97, 98

Offset: 1

Author

Clark Kimberling, Oct 11 2014

Keywords

• nonn
• easy

Examples

			(A248636(k+1) = A248636(k)) = (2, 1, 2, 1, 2, 2, 1, 1, 2, 1, 2, 1, 2, 1, 1, 2,... ), so that A248637 = (2, 4, 7, 8, 10, 12, 14, ... ) and A248638 = (1, 3, 5, 6, 9, 11, 13, ...).
		

Links

• Clark Kimberling, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A248635, A248636, A248630.

Programs

Mathematica

z = 300; p[k_] := p[k] = Sum[(h^3/3^h), {h, 1, k}];
d = N[Table[33/8 - p[k], {k, 1, z/5}], 12]
f[n_] := f[n] = Select[Range[z], 33/8 - p[#] < 1/4^n &, 1];
u = Flatten[Table[f[n], {n, 1, z}]]  (* A248636 *)
d = Differences[u]
v = Flatten[Position[d, 1]] (* A248637 *)
w = Flatten[Position[d, 2]] (* A248638 *)