This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A123685 Counts compositions as described by table A047969; however, only those ending with an odd part are considered. 4
 1, 1, 0, 1, 1, 1, 1, 3, 4, 0, 1, 7, 14, 2, 1, 1, 15, 46, 14, 7, 0, 1, 31, 146, 74, 43, 3, 1, 1, 63, 454, 350, 247, 33, 10, 0, 1, 127, 1394, 1562, 1363, 273, 88, 4, 1, 1, 255, 4246, 6734, 7327, 2013, 724, 60, 13, 0, 1, 511, 12866, 28394, 38683, 13953, 5716, 676, 149, 5, 1, 1 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,8 LINKS Alois P. Heinz, Antidiagonals n = 1..141, flattened EXAMPLE Row four of table A047969 counts the 14 compositions 4 31 13 32 23 33 211 121 112 221 212 122 222 1111 whereas A123685 only counts 31 13 32 33 121 112 122 and 1111 MAPLE g:= proc(b, t, l, m) option remember; `if`(t=0, b*l, add(       g(b, t-1, irem(k, 2), m), k=1..m-1)+g(1, t-1, irem(m, 2), m))     end: A:= (n, k)-> g(0, k, 0, n): seq(seq(A(n, d+1-n), n=1..d), d=1..13); # Alois P. Heinz, Nov 06 2009 MATHEMATICA g[b_, t_, l_, m_] := g[b, t, l, m] = If[t == 0, b*l, Sum[g[b, t-1, Mod[k, 2], m], {k, 1, m-1}] + g[1, t-1, Mod[m, 2], m]]; A[n_, k_] := g[0, k, 0, n]; Table [Table [A[n, d+1-n], {n, 1, d}], {d, 1, 13}] // Flatten (* Jean-François Alcover, Feb 20 2015, after Alois P. Heinz *) CROSSREFS Diagonals include A000012, A059841, A000225, A123684 and A027649. Sequence in context: A175646 A324362 A073234 * A124917 A228550 A189916 Adjacent sequences:  A123682 A123683 A123684 * A123686 A123687 A123688 KEYWORD nonn,tabl AUTHOR Alford Arnold, Oct 11 2006 EXTENSIONS More terms from Alois P. Heinz, Nov 06 2009 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified June 19 13:26 EDT 2019. Contains 324222 sequences. (Running on oeis4.)