1,2

Digits 1, 2 and 3 only appear in members of A005150 so they can be read as numbers in base 4.

Table of n, a(n) for n=1..15.

The fifth term of A005150 is 111221, which is 1385 in base 4 notation.

Cf. A005150.

Sequence in context: A249937 A171812 A221741 * A279707 A329002 A280642

Adjacent sequences: A098094 A098095 A098096 * A098098 A098099 A098100

nonn,base

Axel Harvey, Sep 14 2004

a(13)-a(15) added by Andrew Howroyd, Feb 12 2020

approved