A194626 Numbers n such that next term of Hofstadter's Q-sequence differs by 1.

2, 3, 5, 6, 8, 16, 17, 19, 34, 36, 39, 40, 42, 49, 69, 71, 74, 78, 80, 85, 132, 167, 175, 176, 180, 181, 225, 238, 261, 271, 320, 331, 338, 340, 341, 353, 365, 371, 507, 689, 690, 706, 721, 738, 746, 921, 932, 952, 990, 1012, 1046, 1212, 1351, 1352, 1373

Offset: 1

Author

Reinhard Zumkeller, Sep 15 2011

Keywords

• nonn

Comments

A005185(a(n)+1) = A005185(a(n)) + 1; A081827(a(n)) = 1.

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..200
• Eric Weisstein's World of Mathematics, Hofstadter's Q-Sequence
• Wikipedia, Hofstadter sequence
• Index entries for Hofstadter-type sequences

Crossrefs

Cf. A081828, A081829, A081830.

Programs

Haskell

import Data.List (elemIndices)
a194626 n = a194626_list !! (n-1)
a194626_list = map (+ 1) $ elemIndices 1 a081827_list