A081830 Numbers n such that the n-th term of Hofstadter Q-sequence is < (n+1)-th term.

2, 3, 5, 6, 8, 11, 14, 16, 17, 19, 23, 26, 30, 33, 34, 36, 37, 39, 40, 42, 47, 49, 50, 53, 56, 58, 62, 65, 68, 69, 71, 72, 74, 76, 78, 79, 80, 83, 85, 86, 89, 95, 97, 98, 99, 101, 104, 106, 107, 108, 110, 113, 114, 116, 117, 120, 122, 123, 125, 129, 131, 132, 134, 136

Offset: 1

Author

Benoit Cloitre, Apr 10 2003

Keywords

• nonn

Comments

A005185(a(n)+1) > A005185(a(n)); A081827(a(n)) > 0.

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
• Eric Weisstein's World of Mathematics, Hofstadter's Q-Sequence
• Wikipedia, Hofstadter sequence
• Index entries for Hofstadter-type sequences

Crossrefs

Cf. A081828, A081829, A194626.

Programs

Haskell

import Data.List (findIndices)
a081830 n = a081830_list !! (n-1)
a081830_list = map (+ 1) $ findIndices (> 0) a081827_list
-- Reinhard Zumkeller, Sep 15 2011

Formula

Conjecture : a(n)/n -> 2. a(n)=2n for n=2, 14, 16, 802, 804, 806, 810, 814, 824, 826, 832, 1116, 1120, 1124, 1126, 1130, 1172, 1178, 1228, 1230, 1254, 1258, 1298...