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.

A159861 Square array A(m,n), m>=1, n>=1, read by antidiagonals: A(m,1)=1, A(m,n) is the rank with respect to m of the concatenation of all preceding terms in row m, and the rank of S with respect to m is floor ((S+m-1)/m).

Original entry on oeis.org

1, 1, 1, 11, 1, 1, 1111, 6, 1, 1, 11111111, 58, 4, 1, 1, 1111111111111111, 5829, 38, 3, 1, 1, 11111111111111111111111111111111, 58292915, 3813, 29, 3, 1, 1, 1111111111111111111111111111111111111111111111111111111111111111, 5829291479146458, 38127938, 2833, 23, 2, 1, 1
Offset: 1

Views

Author

Eric Angelini and Alois P. Heinz, Apr 24 2009

Keywords

Examples

			A(3,4) = 38, because A(3,1).A(3,2).A(3,3) = 114, and the rank of 114 with respect to 3 is floor(116/3) = 38.
Square array A(m,n) begins:
  1,  1, 11, 1111, 11111111, 1111111111111111,  ...
  1,  1,  6,   58,     5829,         58292915,  ...
  1,  1,  4,   38,     3813,         38127938,  ...
  1,  1,  3,   29,     2833,         28323209,  ...
  1,  1,  3,   23,     2265,         22646453,  ...
  1,  1,  2,   19,     1870,         18698645,  ...
		

Crossrefs

Row m=2 gives: A156147.
Main diagonal gives: A159862.

Programs

  • Maple
    R:= (S,m)-> iquo(S+m-1, m):
    A:= proc(m, n) option remember; `if`(n=1, 1,
          R(parse(cat(seq(A(m, j), j=1..n-1))), m))
        end:
    seq(seq(A(m, d-m), m=1..d-1), d=1..10);
  • Mathematica
    R[S_, m_] := Quotient[S + m - 1, m];
    A[m_, n_] := If[n == 1, 1, R[ToExpression@StringJoin[ToString /@ Table[A[m, j], {j, 1, n - 1}]], m]];
    Table[Table[A[m, d - m], {m, 1, d - 1}], {d, 1, 10}] // Flatten (* Jean-François Alcover, Feb 13 2023, after Maple code *)