A278060 Relative of Hofstadter Q-sequence: a(n) = n for 1 <= n <= 8; a(n) = a(n-a(n-1)) + a(n-a(n-2)) for n > 8.

1, 2, 3, 4, 5, 6, 7, 8, 3, 9, 10, 5, 11, 6, 7, 12, 14, 10, 8, 14, 18, 12, 15, 8, 23, 13, 10, 17, 13, 25, 16, 19, 20, 13, 19, 29, 18, 17, 30, 24, 24, 20, 23, 26, 20, 27, 24, 26, 38, 13, 28, 38, 30, 20, 42, 35, 19, 45, 30, 32, 29, 45, 23, 32, 40

Offset: 1

Author

Nathan Fox, Nov 10 2016

Keywords

• nonn
• fini
• full

Comments

Similar to Hofstadter's Q-sequence A005185 but with different starting values.

This sequence has exactly 420 terms, since a(420)=430 and computing a(421) would refer to a(-9).

Links

• Nathan Fox, Table of n, a(n) for n = 1..420
• Nathan Fox, Hofstadter-like Sequences over Nonstandard Integers, Talk given at the Rutgers Experimental Mathematics Seminar, November 10 2016.

Crossrefs

Cf. A005185, A278056, A278057, A278058, A278059, A278061, A278062, A278063, A278064, A278065.

Programs

Mathematica

a[n_] := a[n] = If[0 < n < 9, n, a[n-a[n-1]] + a[n-a[n-2]]];
Array[a, 100] (* Paolo Xausa, May 29 2024 *)