OFFSET
0,2
LINKS
G. C. Greubel, Table of n, a(n) for the first 50 rows, flattened
FORMULA
Number triangle T(n,k) = C(floor((n+k)/2), k) * 2^(n-k).
T(n,k) = T(n-1,k-1) + 4*T(n-2,k), T(0,0) = 1, T(1,0) = 2, T(1,1) = 1, T(n,k) = 0 if k<0 or if k>n. - Philippe Deléham, Jan 20 2014
EXAMPLE
Number triangle begins
1;
2, 1;
4, 2, 1;
8, 8, 2, 1;
16, 16, 12, 2, 1;
32, 48, 24, 16, 2, 1;
MATHEMATICA
Table[Binomial[Floor[(n + k)/2], k]*2^(n - k), {n, 0, 49}, {k, 0,
n}] // Flatten (* G. C. Greubel, Oct 13 2017 *)
PROG
(PARI) for(n=0, 10, for(k=0, n, print1(binomial(floor((n+k)/2), k)*2^(n-k), ", "))) \\ G. C. Greubel, Oct 13 2017
CROSSREFS
KEYWORD
AUTHOR
Paul Barry, Sep 30 2006
EXTENSIONS
Terms a(46) onward added by G. C. Greubel, Oct 14 2017
STATUS
approved