1,2

This is a left inverse of A282291, and also the right inverse if A282291 is a permutation of natural numbers, in which case the fallback-clause is unnecessary.

Table of n, a(n) for n=1..63.

For n >= 1, a(A282291(n)) = n.

(PARI) \\ Use the program given in A282291.

Cf. A282291, A302854.

Sequence in context: A239887 A241012 A064745 * A218454 A115425 A116418

Adjacent sequences: A304087 A304088 A304089 * A304091 A304092 A304093

nonn

Antti Karttunen, May 17 2018

approved