A087845 a[n] =a[Min[n-1,Abs[n - a[n-1]]]] + a[a[a[Abs[n - a[n-3]]]]]

1, 1, 1, 2, 2, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9, 9, 11, 10, 11, 11, 11, 11, 11, 11, 11, 11, 11, 13, 11, 13, 12, 13, 13, 13, 13, 13, 13, 13, 13, 13, 15, 13, 15, 13, 15, 14, 15, 15, 15, 15, 15, 15, 15, 15

Offset

1,4

Comments

The fourth recursive of the second term of the skip one Hofstadter Q.

Links

Table of n, a(n) for n=1..85.

Mathematica

Hofstadter3[n_Integer?Positive] := Hofstadter3[n] = Hofstadter3[Min[n-1, Abs[n - Hofstadter3[n-1]]]] + Hofstadter3[Hofstadter3[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, A081831.

Sequence in context: A002024 A123578 A087836 * A130146 A113764 A130148

Adjacent sequences: A087842 A087843 A087844 * A087846 A087847 A087848

Keyword

nonn

Author

Roger L. Bagula, Oct 07 2003

Status

approved