A239965 Where the n-th nonprime occurs in the nonprime EKG sequence A240024.

1, 2, 3, 4, 7, 5, 6, 10, 8, 11, 9, 12, 15, 13, 14, 18, 21, 16, 20, 17, 22, 25, 23, 19, 24, 28, 26, 29, 27, 30, 33, 31, 32, 43, 34, 37, 35, 36, 40, 44, 38, 45, 39, 46, 49, 47, 41, 48, 52, 50, 42, 51, 53, 56, 54, 60, 55, 57, 64, 58, 59, 74, 62, 65, 61, 63, 71

Offset: 1

Author

Reinhard Zumkeller, Apr 30 2014

Keywords

• nonn

Comments

A240024(a(n)) = A018252(n);

a permutation of the natural numbers with inverse A238862: a(A238862(n))=A238862(a(n))=n.

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
• Index entries for sequences that are permutations of the natural numbers

Crossrefs

Cf. A239943 (fixed points).

Programs

Haskell

import Data.List (elemIndex); import Data.Maybe (fromJust)
a239965 = (+ 1) . fromJust . (`elemIndex` a240024_list) . a018252