A020336 Numbers whose base-8 representation is the juxtaposition of two identical strings.

9, 18, 27, 36, 45, 54, 63, 520, 585, 650, 715, 780, 845, 910, 975, 1040, 1105, 1170, 1235, 1300, 1365, 1430, 1495, 1560, 1625, 1690, 1755, 1820, 1885, 1950, 2015, 2080, 2145, 2210, 2275, 2340, 2405, 2470, 2535, 2600, 2665, 2730, 2795, 2860, 2925, 2990, 3055

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Formula

a(n) = n*8^floor(log_8(n)+1) + n. - Ilya Gutkovskiy, Jan 26 2018

Example

650_10 = 1212_8. - Jon E. Schoenfield, Feb 12 2021

Mathematica

a[n_] := n + n*8^Floor[Log[8, n] + 1]; Array[a, 50] (* Amiram Eldar, Apr 06 2021 *)

Crossrefs

Cf. A020330, A020331, A020332, A020333, A020334, A020335, A020337, A020338.

Sequence in context: A217373 A033021 A031493 * A044834 A033006 A259727

Adjacent sequences: A020333 A020334 A020335 * A020337 A020338 A020339

Keyword

nonn,base

Author

David W. Wilson, Melia Aldridge (ma38(AT)spruce.evansville.edu)

Status

approved