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.

Showing 1-2 of 2 results.

A324019 Triangle T(n,k) read by rows giving the number of k-digit zeroless polydivisible numbers in base n with 1 <= k <= n-1.

Original entry on oeis.org

1, 2, 2, 3, 3, 3, 4, 8, 10, 10, 5, 10, 10, 10, 10, 6, 18, 36, 52, 62, 62, 7, 21, 49, 49, 68, 68, 68, 8, 32, 64, 128, 205, 205, 233, 233, 9, 36, 108, 216, 216, 324, 416, 416, 416, 10, 50, 166, 416, 832, 1382, 1967, 2465, 2726, 2726, 11, 55, 165, 330, 726, 726, 1140, 1140, 1140, 1140, 1140
Offset: 2

Views

Author

Seiichi Manyama, Sep 01 2019

Keywords

Comments

For k >= n there is no k-digit zeroless polydivisible number in base n.

Examples

			Triangle begins:
n\k  | 1   2    3    4    5    6    7    8    9
-----+------------------------------------------
   2 | 1;
   3 | 2,  2;
   4 | 3,  3,   3;
   5 | 4,  8,  10,  10;
   6 | 5, 10,  10,  10,  10;
   7 | 6, 18,  36,  52,  62,  62;
   8 | 7, 21,  49,  49,  68,  68,  68;
   9 | 8, 32,  64, 128, 205, 205, 233, 233;
  10 | 9, 36, 108, 216, 216, 324, 416, 416, 416;
		

Crossrefs

Row sums give A324020.

A271374 Total number of polydivisible numbers in base n.

Original entry on oeis.org

3, 16, 38, 128, 324, 1068, 2569, 8381, 20457, 58174, 148059, 441493, 916146, 3722968, 8407790, 23909586, 64576509, 178009925, 466027279, 1409607602, 3507905894, 9694292108, 25391646456, 73838562312, 191793924162, 550333004128
Offset: 2

Views

Author

Martin Renner, Apr 05 2016

Keywords

Examples

			There are a(10) = 20457 polydivisible numbers in base 10, which are listed in A144688.
		

Crossrefs

Row sums of A271373.

Formula

a(n) = Sum_{k=1..A109783(n)} A271373(n,k).
a(n) ~ (n-1)*(exp(n)-1)/n.

Extensions

a(16) from Seiichi Manyama, Sep 01 2019
a(17)-a(18) from Seiichi Manyama, Sep 02 2019
a(19)-a(27) from Max Alekseyev, Sep 08 2021
Showing 1-2 of 2 results.