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.

A054659 Increasing sequence with no repeating digits and no digits shared with previous term.

Original entry on oeis.org

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 23, 40, 51, 60, 71, 80, 91, 203, 415, 602, 713, 802, 913, 2045, 3167, 4025, 6137, 8024, 9135, 20467, 31589, 40267, 51389, 60247, 81359
Offset: 1

Views

Author

Henry Bottomley, Apr 18 2000

Keywords

Comments

a(11)=23 since a(10)=10 and any number from 11 to 21 would share a digit between the two terms while 22 has a repeated digit

Crossrefs

Cf. A030283.

Programs

  • Python
    def ok(s, t): return len(set(t)) == len(t) and len(set(s+t)) == len(s+t)
    def agen(): # generator of complete sequence of terms
        an, MAX = 0, 987654321
        while True:
            if an < MAX: yield an
            else: return
            an, s = an+1, str(an)
            MAX = 10**(10-len(s))
            while an < MAX and not ok(s, str(an)): an += 1
    print(list(agen())) # Michael S. Branicky, Jun 30 2022