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.

A163621 Square array read by antidiagonals: Write n and m in binary with n on the left. Concatenate. a(n,m) is the decimal equivalent of the result.

Original entry on oeis.org

3, 5, 6, 7, 10, 7, 9, 14, 11, 12, 11, 18, 15, 20, 13, 13, 22, 19, 28, 21, 14, 15, 26, 23, 36, 29, 22, 15, 17, 30, 27, 44, 37, 30, 23, 24, 19, 34, 31, 52, 45, 38, 31, 40, 25, 21, 38, 35, 60, 53, 46, 39, 56, 41, 26, 23, 42, 39, 68, 61, 54, 47, 72, 57, 42, 27, 25, 46, 43, 76, 69
Offset: 1

Views

Author

Leroy Quet, Aug 01 2009

Keywords

Examples

			Rows 1 through 5 written in binary (with a "|" between n and m written in binary):
1|1, 1|10, 1|11, 1|100, 1|101,...
10|1, 10|10, 10|11, 10|100, 10|101,...
11|1, 11|10, 11|11, 11|100, 11|101,...
100|1, 100|10, 100|11, 100|100, 100|101,...
101|1, 101|10, 101|11, 101|100, 101|101,...
Ignore the "|" in each binary number to get the binary equivalent of the terms in the table.
		

Programs

  • Maple
    A163621 := proc(n,m) L := [op(convert(m,base,2) ), op(convert(n,base,2) ) ] ; add(op(i,L)*2^(i-1),i=1..nops(L)) ; end: seq(seq(A163621(d-m+1,m),m=1..d),d=1..17) ; # R. J. Mathar, Sep 27 2009
  • Mathematica
    Table[FromDigits[Join @@ IntegerDigits[{#, m}, 2], 2] &[k - m + 1], {k, 12}, {m, k}] // Flatten (* Michael De Vlieger, Dec 26 2019 *)

Extensions

Extended by R. J. Mathar, Sep 27 2009