login
A248635
Numbers k such that A248633(k+1) = A248633(k) + 2.
4
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, 43, 45, 47, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 69, 71, 73, 75, 77, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 100, 102, 104, 106, 108, 110, 112, 114, 116
OFFSET
1,2
LINKS
EXAMPLE
(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, ...).
MATHEMATICA
z= 300; p[k_] := p[k] = Sum[(h^2/4^h), {h, 1, k}];
d = N[Table[20/27 - p[k], {k, 1, z/5}], 12];
f[n_] := f[n] = Select[Range[z], 20/27 - p[#] < 1/8^n &, 1];
u = Flatten[Table[f[n], {n, 1, z}]] (* A248633 *)
d = Differences[u]
Flatten[Position[d, 1]] (* A248634 *)
Flatten[Position[d, 2]] (* A248635 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, Oct 11 2014
STATUS
approved