A330740 a(n) = min(n, A004488(n)), where A004488(n) is base-3 sum n+n without carries.

0, 1, 1, 3, 4, 5, 3, 5, 4, 9, 10, 11, 12, 13, 14, 15, 16, 17, 9, 11, 10, 15, 17, 16, 12, 14, 13, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 27, 29, 28, 33, 35, 34, 30, 32, 31, 45, 47, 46, 51, 53, 52, 48, 50, 49, 36, 38, 37, 42, 44, 43, 39, 41, 40, 81

Offset

0,4

Comments

After the initial zero, sequence contains only terms of A132141, each appearing exactly twice.

Links

Antti Karttunen, Table of n, a(n) for n = 0..59048

Formula

a(n) = min(n, A004488(n)).

Prog

(PARI) A330740(n) = min(n, subst(Pol(apply(x->(3-x)%3, digits(n, 3)), 'x), 'x, 3));

Crossrefs

Cf. A004488, A132141.

Central diagonal of A325825 (after the initial zero).

Sequence in context: A033706 A354597 A121890 * A178231 A343262 A298734

Adjacent sequences: A330737 A330738 A330739 * A330741 A330742 A330743

Keyword

nonn,base

Author

Antti Karttunen, Jan 11 2020

Status

approved