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.

A082185 Triangle read by rows: n-th row contains concatenations of nonempty subsets of {1, 2, ..., n}, ordered first by size and then lexicographically.

Original entry on oeis.org

1, 1, 2, 12, 1, 2, 3, 12, 13, 23, 123, 1, 2, 3, 4, 12, 13, 14, 23, 24, 34, 123, 124, 134, 234, 1234, 1, 2, 3, 4, 5, 12, 13, 14, 15, 23, 24, 25, 34, 35, 45, 123, 124, 125, 134, 135, 145, 234, 235, 245, 345, 1234, 1235, 1245, 1345, 2345, 12345, 1, 2, 3, 4, 5, 6, 12, 13, 14, 15
Offset: 1

Views

Author

M. Khoshnevisan (m.khoshnevisan(AT)griffith.edu.au), May 10 2003

Keywords

Examples

			Triangle T(n,k) begins:
  1;
  1, 2, 12;
  1, 2,  3, 12, 13, 23, 123;
  1, 2,  3,  4, 12, 13,  14, 23, 24, 34, 123, 124, 134, 234, 1234;
  ...
		

References

  • F. Smarandache and J. Dezert, Advances and Applications of DSmT for Information Fusion, Vol. 1, ARPress, 2004, pp. 42-46.

Programs

  • Maple
    T:= n-> map(x-> parse(cat(x[])),
           [seq(combinat[choose]([$1..n], i)[], i=1..n)])[]:
    seq(T(n), n=1..6);  # Alois P. Heinz, Jan 30 2023

Extensions

More terms from David Wasserman, Aug 19 2004