A064787 Inverse permutation to A053212.

1, 2, 3, 4, 6, 5, 11, 7, 8, 9, 23, 10, 31, 15, 13, 12, 58, 14, 74, 16, 18, 29, 122, 17, 25, 40, 21, 22, 224, 19, 267, 20, 38, 69, 33, 24, 453, 89, 49, 26, 636, 28, 737, 43, 30, 141, 995, 27, 53, 35, 84, 57, 1523, 34, 59, 36, 108, 257, 2244, 32, 2528, 310, 41, 37, 77, 52

Offset: 1

Author

N. J. A. Sloane, Oct 20 2001

Keywords

• easy
• nonn

Comments

a(n) is the index of A005179(n) in A007416; equivalently, a(n) is the number of minimal numbers (numbers in A007416) that are <= A005179(n). - Jianing Song, Aug 16 2022

Examples

			a(23) = 122 because d(n) (A000005(n)) takes 121 different values before it first reaches 23 (at n = 2^22).
		

Links

• Amiram Eldar, Table of n, a(n) for n = 1..148
• Index entries for sequences that are permutations of the natural numbers.

Crossrefs

Cf. A053212, A005179, A007416, A000005.

Programs

Haskell

import Data.List (elemIndex); import Data.Maybe (fromJust)
a064787 = (+ 1) . fromJust . (`elemIndex` a053212_list)
-- Reinhard Zumkeller, Apr 18 2015

Extensions

More terms from Naohiro Nomoto, Oct 31 2001

More terms from David Wasserman, Aug 14 2002