A352417 Inverse permutation to A352416.

0, 1, 3, 4, 2, 9, 10, 12, 13, 5, 6, 7, 27, 28, 30, 31, 11, 36, 37, 39, 40, 14, 15, 16, 18, 19, 21, 22, 8, 81, 82, 84, 85, 29, 90, 91, 93, 94, 32, 33, 34, 108, 109, 111, 112, 38, 117, 118, 120, 121, 41, 42, 43, 45, 46, 48, 49, 17, 54, 55, 57, 58, 20, 63, 64, 66

Offset: 0

Author

Rémy Sigrist, Mar 15 2022

Keywords

• nonn
• base

Examples

			A352416(7) = 11, so a(11) = 7.
		

Links

• Rémy Sigrist, Table of n, a(n) for n = 0..10000
• Index entries for sequences that are permutations of the natural numbers

Crossrefs

Cf. A000129, A317204, A352416.

Programs

PARI

a(n) = { my (p=[1, 2]); for (k=2, oo, if (n<=p[k], my (v=0, d); while (n, v+=3^k*d=n\p[k]; if (d==2, v/=3); n-=d*p[k]; k--); return (v/3), p = concat(p, 2*p[k]+p[k-1]))) }