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A158860 Triangle T(n,k)= ( 1 +T(n-1,k)*T(n,k-1) ) / T(n-1,k-1) initialized by T(n,0)=3n-2, T(n,k)=0 if k>=n, read by rows 0<=k<n. 1
1, 4, 1, 7, 2, 1, 10, 3, 2, 1, 13, 4, 3, 2, 1, 16, 5, 4, 3, 2, 1, 19, 6, 5, 4, 3, 2, 1, 22, 7, 6, 5, 4, 3, 2, 1, 25, 8, 7, 6, 5, 4, 3, 2, 1, 28, 9, 8, 7, 6, 5, 4, 3, 2, 1 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Row sums are in A052905.

REFERENCES

H. S. M. Coxeter, Regular Polytopes, 3rd ed., Dover, NY, 1973, pp 159-162.

LINKS

Table of n, a(n) for n=1..55.

FORMULA

T(n,k) = n-k, k>=1. - R. J. Mathar, Jul 11 2012

EXAMPLE

1;

4, 1;

7, 2, 1;

10, 3, 2, 1;

13, 4, 3, 2, 1;

16, 5, 4, 3, 2, 1;

19, 6, 5, 4, 3, 2, 1;

22, 7, 6, 5, 4, 3, 2, 1;

25, 8, 7, 6, 5, 4, 3, 2, 1;

28, 9, 8, 7, 6, 5, 4, 3, 2, 1;

MAPLE

A158860 := proc(n, k)

    option remember;

    if k = 0 then

        3*n-2 ;

    elif k >= n then

        0 ;

    else

        (1+procname(n-1, k)*procname(n, k-1))/procname(n-1, k-1) ;

    end if;

end proc: # R. J. Mathar, Jul 11 2012

MATHEMATICA

Clear[e, n, k];

e[n_, 0] := 3*n - 2;

e[n_, k_] := 0 /; k >= n;

e[n_, k_] := (e[n - 1, k]*e[n, k - 1] + 1)/e[n - 1, k - 1];

Table[Table[e[n, k], {k, 0, n - 1}], {n, 1, 10}];

Flatten[%]

CROSSREFS

Cf. A130303

Sequence in context: A329347 A050356 A245838 * A037022 A037023 A143971

Adjacent sequences:  A158857 A158858 A158859 * A158861 A158862 A158863

KEYWORD

nonn,easy,tabl

AUTHOR

Roger L. Bagula and Gary W. Adamson, Mar 28 2009

STATUS

approved

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Last modified February 22 05:52 EST 2020. Contains 332116 sequences. (Running on oeis4.)