A086841 a(n) = a((a(n-2))*mod(n,2)+a(n-1)*(1-mod(n,2))) + a((n - a(n-2))*mod(n,2)+(n-a(n-1))*(1-mod(n,2))).

1, 1, 2, 2, 3, 4, 4, 4, 5, 6, 7, 7, 8, 8, 8, 8, 9, 10, 11, 12, 13, 13, 14, 14, 15, 15, 15, 16, 16, 16, 16, 16, 17, 18, 19, 20, 21, 22, 23, 23, 24, 24, 25, 26, 27, 26, 27, 28, 28, 29, 30, 29, 30, 30, 31, 31, 31, 31, 32, 32, 32, 32, 32, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 41, 42

Offset: 1

Author

Roger L. Bagula, Sep 15 2003

Keywords

• nonn

Comments

Let M = A005229, C = A004001. Then we may define a pair of new sequences by o1 = M*mod(n,2)+C*(1-mod(n,2)) (this sequence), o2 = C*mod(n,2)+M*(1-mod(n,2)) (A086525 - or is it A086335?).

Links

• Index entries for Hofstadter-type sequences

Crossrefs

Cf. A005229, A086525, A086335. Different from A004001.

Programs

Mathematica

digits = 200 Mc[n_Integer?Positive] := Mc[n] = Mc[( Mc[n-2])*(Mod[n, 2])+Mc[n-1]*(1-Mod[n, 2])] + Mc[(n - Mc[n-2])*(Mod[n, 2])+(n-Mc[n-1])*(1-Mod[n, 2])] Mc[1] = Mc[2] = 1 a1=Table[Mc[n], {n, 1, digits}]

Extensions

Edited by N. J. A. Sloane, Nov 07 2007