A267759 - OEIS

A267759

Numbers of the form 10k+u where 0 <= u <= 9 and k has a digit > u or a digit 1 followed by a digit < u.

10, 20, 21, 30, 31, 32, 40, 41, 42, 43, 50, 51, 52, 53, 54, 60, 61, 62, 63, 64, 65, 70, 71, 72, 73, 74, 75, 76, 80, 81, 82, 83, 84, 85, 86, 87, 90, 91, 92, 93, 94, 95, 96, 97, 98, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 145

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

This is the range of A268449, which is the main motivation for registering this sequence in the OEIS.

LINKS

Table of n, a(n) for n=1..87.

MATHEMATICA

Select[Range[10, 150], Last@ #2 > First@ #1 || If[Length@ #2 >= 2, And[#2[[-2]] == 1, Last@ #2 < First@ #1]] & @@ TakeDrop[IntegerDigits@ #, -1] &] (* Version 10.2, or *)

Select[Range@ 150, If[Length@ # < 2, False, #[[-2]] > Last@ # || If[Length@ # >= 3, And[#[[-3]] == 1, #[[-2]] < Last@ #]]] &@ IntegerDigits@ # &] (* Michael De Vlieger, Feb 05 2016 *)

PROG

(PARI) is_A267759(n)=vecmax(n=digits(n))>n[#n] || sum(i=1, #n-2, n[i]==1 && n[i+1]<n[#n])

CROSSREFS

Sequence in context: A098176 A362669 A132782 * A297270 A071590 A210589

Adjacent sequences: A267756 A267757 A267758 * A267760 A267761 A267762

KEYWORD

nonn,base

AUTHOR

M. F. Hasler, Feb 05 2016

STATUS

approved