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 A138778 Triangle read by rows: T(n,k)=k*binomial(n-2k,3k) (n>=5, 1<=k<=n/5). 0
 1, 4, 10, 20, 35, 56, 2, 84, 14, 120, 56, 165, 168, 220, 420, 286, 924, 3, 364, 1848, 30, 455, 3432, 165, 560, 6006, 660, 680, 10010, 2145, 816, 16016, 6006, 4, 969, 24752, 15015, 52, 1140, 37128, 34320, 364 (list; graph; refs; listen; history; text; internal format)
 OFFSET 5,2 COMMENTS Row n contains floor(n/5) terms. Row sums yield A137359. REFERENCES D. E. Knuth, The Art of Computer Programming, Vol. 4A, Section 7.1.4. LINKS MAPLE T:=proc(n, k) options operator, arrow: k*binomial(n-2*k, 3*k) end proc: for n from 5 to 22 do seq(T(n, k), k=1..(1/5)*n) end do; # yields sequence in triangular form MATHEMATICA Flatten[Table[k*Binomial[n-2k, 3k], {n, 5, 30}, {k, 1, n/5}]] (* Harvey P. Dale, Dec 20 2014 *) CROSSREFS Cf. A137359. Sequence in context: A038406 A301007 A127764 * A301244 A038409 A201722 Adjacent sequences:  A138775 A138776 A138777 * A138779 A138780 A138781 KEYWORD nonn,tabf AUTHOR Emeric Deutsch, May 10 2008 STATUS approved

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Last modified April 10 16:05 EDT 2021. Contains 342845 sequences. (Running on oeis4.)