

A131779


Triangle read by rows: T(n,k) = 2*A065941(n1,k1)  (1)^(n+k).


3



1, 3, 1, 1, 3, 1, 3, 1, 5, 1, 1, 3, 5, 5, 1, 3, 1, 9, 5, 7, 1, 1, 3, 9, 9, 11, 7, 1, 3, 1, 13, 9, 21, 11, 9, 1, 1, 3, 13, 13, 29, 21, 19, 9, 1, 3, 1, 17, 13, 43, 29, 41, 19, 11, 1, 1, 3, 17, 17, 55, 43, 69, 41, 29, 11, 1, 3, 1, 21, 17, 73, 55, 113, 69, 71, 29, 13, 1
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OFFSET

1,2


LINKS



FORMULA

T(n,k) = 2*binomial(n1floor(k/2), floor((k1)/2))  (1)^(n+k).  Andrew Howroyd, Sep 08 2018


EXAMPLE

First few rows of the triangle are:
1;
3, 1;
1, 3, 1;
3, 1, 5, 1;
1, 3, 5, 5, 1;
3, 1, 9, 5, 7, 1;
1, 3, 9, 9, 11, 7, 1;
...


PROG

(PARI) T(n, k) = {if(k<=n, 2*binomial(n1k\2, (k1)\2)  (1)^(n+k), 0)} \\ Andrew Howroyd, Sep 08 2018


CROSSREFS



KEYWORD



AUTHOR



EXTENSIONS

a(28)a(29) corrected and terms a(56) and beyond from Andrew Howroyd, Sep 08 2018


STATUS

approved



