A076701 Values of n not reached in the Hofstadter sequence (A005185).

7, 13, 15, 18, 27, 29, 34, 36, 49, 51, 59, 67, 70, 74, 81, 89, 95, 97, 98, 99, 102, 103, 117, 126, 127, 131, 134, 141, 142, 145, 150, 158, 163, 166, 181, 183, 189, 191, 195, 197, 198, 199, 205, 207, 209, 213, 224, 225, 232, 247, 259, 265, 267, 270, 274, 281

Offset: 1

Author

Benoit Cloitre, Oct 26 2002

Keywords

• nonn

Comments

For any n, there is no solution to a(n) = A005185(x). Does lim_{n -> infinity} a(n)/n exist?

Plotting a(n)/n for the first 6 billion terms, it appears to be converging to ~7.39. - Benjamin Chaffin, Sep 17 2019

Links

• Benjamin Chaffin, Table of n, a(n) for n = 1..13805
• Benjamin Chaffin, Log scale plot of a(n)/n from 1 .. 6*10^9
• Benjamin Chaffin, Log scale plot of a(n)/n from 1000000 .. 6*10^9

Crossrefs

Cf. A005185.

Programs

Mathematica

a[1] = a[2] = 1; a[n_] := a[n] = a[n - a[n - 1]] + a[n - a[n - 2]]; t = Table[a[n], {n, 1000}]; Take[ Complement[ Range@ 502, Union@ t], 56]