A382938 Nonnegative integers such that every odd digit except the leftmost is immediately preceded by a larger digit.

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 16, 18, 20, 21, 22, 24, 26, 28, 30, 31, 32, 34, 36, 38, 40, 41, 42, 43, 44, 46, 48, 50, 51, 52, 53, 54, 56, 58, 60, 61, 62, 63, 64, 65, 66, 68, 70, 71, 72, 73, 74, 75, 76, 78, 80, 81, 82, 83, 84, 85, 86, 87, 88, 90, 91, 92, 93, 94, 95

Offset: 1

Author

Paolo Xausa, Apr 14 2025

Keywords

• nonn
• base
• easy

Links

• Paolo Xausa, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A382937 (complement).

Cf. A377912, A382465, A382624, A383062, A383246, A383248, A383250, A383501.

Programs

Mathematica

A382938Q[k_] := FreeQ[Partition[IntegerDigits[k], 2, 1], {i_, j_?OddQ} /; i <= j];
Select[Range[0, 100], A382938Q]

Python

def ok(n):
    s = str(n)
    return all(s[i+1] < s[i] for i in range(len(s)-1) if s[i+1] in "13579")
print([k for k in range(96) if ok(k)]) # Michael S. Branicky, Apr 14 2025