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.

A256867 Numbers divisible by prime(d+1) for each digit d of their base-7 representation.

Original entry on oeis.org

0, 15, 57, 100, 168, 182, 396, 450, 624, 700, 750, 800, 840, 1050, 1176, 1190, 1274, 1485, 1540, 1716, 2520, 2652, 2760, 2772, 2814, 2850, 2898, 2970, 3150, 3486, 3570, 3861, 4173, 4368, 4488, 4860, 4900, 4940, 4970, 5160, 5250, 5490, 5595, 5600, 5880, 5950, 6435, 6630, 7224, 7350, 7560, 7602, 7910, 8050, 8232, 8330
Offset: 1

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Author

M. F. Hasler, Apr 11 2015

Keywords

Comments

The base-7 variant of A256882 - A256884, A256865 - A256870 in bases 2, ..., 10.
A variant of A256877 where digits 0 are forbidden and divisibility by prime(d) is required.

Crossrefs

Programs

  • Mathematica
    Select[Range[0,9000],AllTrue[#/Prime[IntegerDigits[#,7]+1],IntegerQ]&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Sep 17 2020 *)
  • PARI
    is(n,b=7)=!for(i=1,#d=Set(digits(n,b)),n%prime(d[i]+1)&&return)