cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A383245 Nonnegative integers that contain the digit 0, or an even digit d immediately followed by a digit >= d.

Original entry on oeis.org

0, 10, 20, 22, 23, 24, 25, 26, 27, 28, 29, 30, 40, 44, 45, 46, 47, 48, 49, 50, 60, 66, 67, 68, 69, 70, 80, 88, 89, 90, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 120, 122, 123, 124, 125, 126, 127, 128, 129, 130, 140, 144, 145, 146, 147, 148, 149, 150, 160, 166
Offset: 1

Views

Author

Paolo Xausa, Apr 20 2025

Keywords

Comments

Conjecture: these are the numbers missing from A342043.

Crossrefs

Programs

  • Mathematica
    A383245Q[k_] := MemberQ[#, 0] || MemberQ[Partition[#, 2, 1], {i_?EvenQ, j_} /; j >= i] & [IntegerDigits[k]];
    Select[Range[0, 200], A383245Q]
  • Python
    def ok(n):
        if n%10 == 0: return True
        s = str(n)
        return any(d in "02468" and s[i]>=d for i, d in enumerate(s, 1) if i < len(s))
    print([k for k in range(167) if ok(k)]) # Michael S. Branicky, Apr 28 2025