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.

A253190 Triangle T(n, m)=Sum_{k=1..(n-m)/2} C(m+k-1, k)*T((n-m)/2, k), T(n,n)=1.

Original entry on oeis.org

1, 0, 1, 1, 0, 1, 0, 2, 0, 1, 1, 0, 3, 0, 1, 0, 3, 0, 4, 0, 1, 2, 0, 6, 0, 5, 0, 1, 0, 6, 0, 10, 0, 6, 0, 1, 3, 0, 13, 0, 15, 0, 7, 0, 1, 0, 11, 0, 24, 0, 21, 0, 8, 0, 1, 5, 0, 27, 0, 40, 0, 28, 0, 9, 0, 1, 0, 20, 0, 55, 0, 62, 0, 36, 0, 10, 0, 1
Offset: 1

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Author

Vladimir Kruchinin, Mar 24 2015

Keywords

Examples

			1;
0, 1;
1, 0, 1;
0, 2, 0, 1;
1, 0, 3, 0, 1;
0, 3, 0, 4, 0, 1;
2, 0, 6, 0, 5, 0, 1;
		

Crossrefs

Cf. A000621 (row sums), A003600, A253184, A253189.

Programs

  • Maple
    A253190 := proc(n,m)
        option remember;
        if n = m then
            1;
        elif type(n-m,'odd') then
            0 ;
        else
            add(binomial(m+k-1,k)*procname((n-m)/2,k),k=1..(n-m)/2) ;
        end if;
    end proc: # R. J. Mathar, Dec 16 2015
  • Maxima
    T(n, m):=if n=m then 1 else sum(binomial(m+k-1, k)*T((n-m)/2, k), k, 1, (n-m)/2);

Formula

G.f.: A(x)^m=Sum_{n>=m} T(n,m)x^n, A(x)=Sum_{n>0} a(n)*x^(2*n-1), a(n) - is A000621.