A087829 a[n] =a[a[Abs[n - a[n-1]]]] + a[Abs[n - a[n-4]]]

1, 1, 1, 1, 2, 3, 4, 5, 5, 5, 5, 5, 7, 6, 7, 7, 7, 7, 7, 11, 8, 10, 11, 11, 10, 11, 11, 11, 11, 11, 16, 12, 15, 15, 12, 16, 15, 16, 16, 16, 16, 16, 16, 16, 16, 16, 23, 17, 20, 20, 18, 19, 22, 20, 20, 22, 17, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 34, 24, 27, 27, 27, 25, 27

Offset

0,5

Comments

A triple recursion of the skip two Hofstadter Q sequence.

Links

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

Mathematica

Hofstadter14[n_Integer?Positive] := Hofstadter14[n] = Hofstadter14[Hofstadter14[Abs[n - Hofstadter14[n-1]]]] + Hofstadter14[Abs[n - Hofstadter14[n-4]]] Hofstadter14[0] = Hofstadter14[1] = Hofstadter14[2]= Hofstadter14[3]= Hofstadter14[4]= 1 digits=200 ta=Table[Hofstadter14[n], {n, 1, digits}]

Crossrefs

Cf. A005185.

Sequence in context: A067854 A194214 A251416 * A078474 A087177 A180600

Adjacent sequences: A087826 A087827 A087828 * A087830 A087831 A087832

Keyword

nonn

Author

Roger L. Bagula, Oct 06 2003

Status

approved