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A158786 A recursive sequence: e(n,k)=(e(n - 1, k)*e(n, k - 1) + 1)/e(n - 1, k - 1) 0
1, 25, 4, 1, 100, 25, 11, 4, 1, 275, 100, 25, 29, 11, 4, 1, 725, 275, 100, 25, 76, 29, 11, 4, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,2

COMMENTS

Row sums are:

{1, 25, 5, 125, 16, 400, 45, 1125, 121,...}.

REFERENCES

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

LINKS

Table of n, a(n) for n=2..26.

FORMULA

e(n,k)=(e(n - 1, k)*e(n, k - 1) + 1)/e(n - 1, k - 1);

out_(n,m)=5*(e(n,m)

EXAMPLE

{1},

{25},

{4, 1},

{100, 25},

{11, 4, 1},

{275, 100, 25},

{29, 11, 4, 1},

{725, 275, 100, 25},

{76, 29, 11, 4, 1}

MATHEMATICA

Clear[e, n, k];

e[n_, 0] := Sqrt[5]*(GoldenRatio^n + GoldenRatio^(-n));

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[5*Rationalize[N[e[n, k]]], {k, Mod[ n, 2] + 1, n - 1, 2}], {n, 1, 10}];

Flatten[%]

CROSSREFS

A158753, A002878

Sequence in context: A040615 A317325 A040610 * A040611 A236176 A040608

Adjacent sequences:  A158783 A158784 A158785 * A158787 A158788 A158789

KEYWORD

nonn,tabf,uned

AUTHOR

Roger L. Bagula and Gary W. Adamson, Mar 26 2009

STATUS

approved

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Last modified November 28 20:45 EST 2021. Contains 349415 sequences. (Running on oeis4.)