A283895 Relative of Hofstadter Q-sequence: a(1) = 41, a(2) = 2; thereafter a(n) = a(n-a(n-1)) + a(n-a(n-2)).

41, 2, 41, 2, 41, 2, 41, 2, 41, 2, 41, 2, 41, 2, 41, 2, 41, 2, 41, 2, 41, 2, 41, 2, 41, 2, 41, 2, 41, 2, 41, 2, 41, 2, 41, 2, 41, 2, 41, 2, 41, 43, 2, 84, 2, 84, 2, 84, 2, 84, 2, 84, 2, 84, 2, 84, 2, 84, 2, 84, 2, 84, 2, 84, 2, 84, 2, 84, 2, 84, 2, 84, 2, 84, 2

Offset: 1

Author

Nathan Fox, Mar 19 2017

Keywords

• nonn

Comments

In calculating terms of this sequence, use the convention that a(n)=0 for n<=0.

Most terms in this sequence alternate between 2 and a large constant. Such runs of terms are eventually separated by either 224 or 562 other terms, and each run is approximately twice as long as the previous.

Links

• Nathan Fox, Table of n, a(n) for n = 1..50000

Crossrefs

Cf. A005185, A278066, A278067, A278068, A283893, A283894, A283896, A283897.

Programs

Maple

A283895:=proc(n) option remember: if n <= 0 then 0: elif n = 1 then 41: elif n = 2 then 2: else A283895(n-A283895(n-1)) + A283895(n-A283895(n-2)): fi: end: