A087827 a(n) = a(a(Min(n-1,Abs(n-a(n-1)))))+a(Abs(n-a(n-3))).

1, 1, 1, 2, 3, 4, 4, 4, 4, 6, 5, 6, 6, 6, 6, 10, 7, 9, 8, 10, 9, 10, 10, 10, 10, 16, 10, 13, 12, 14, 13, 14, 12, 15, 15, 14, 16, 16, 16, 16, 16, 26, 14, 19, 18, 20, 19, 20, 18, 19, 19, 21, 21, 21, 21, 21, 20, 26, 22, 26, 21, 26, 26, 24, 26, 26, 24, 34, 20, 28, 22, 29, 26, 31, 28, 29

Offset

0,4

Comments

A triple recursion of the skip one Hofstadter Q.

Links

Table of n, a(n) for n=0..75.

Mathematica

Hofstadter3[n_Integer?Positive] := Hofstadter3[n] = Hofstadter3[Hofstadter3[Min[n-1, Abs[n - Hofstadter3[n-1]]]]] + Hofstadter3[Abs[n - Hofstadter3[n-3]]]
Hofstadter3[0]=Hofstadter3[1] = Hofstadter3[2]= Hofstadter3[3]= 1
digits=200
ta=Table[Hofstadter3[n], {n, 1, digits}]

Crossrefs

Cf. A005185.

Sequence in context: A195849 A376571 A372450 * A136528 A263252 A276334

Adjacent sequences: A087824 A087825 A087826 * A087828 A087829 A087830

Keyword

nonn

Author

Roger L. Bagula, Oct 06 2003

Status

approved