1,2

Only numbers that occur just once are the powers of two (A000079).

Antti Karttunen, Table of n, a(n) for n = 1..10081

(Scheme, with Antti Karttunen's IntSeq-library)

(define A241920 (COMPOSE-FUNS (LEAST-GTE-I 0 1 A203623) -1+))

Cf. A082288, A061395, A203623, A067255, A241918, A241914, A241915.

Sequence in context: A267861 A253548 A083036 * A202305 A195778 A165706

Adjacent sequences: A241917 A241918 A241919 * A241921 A241922 A241923

nonn

Antti Karttunen, May 01 2014

approved