This site is supported by donations to The OEIS Foundation.

 Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing. Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A299967 Number of normal generalized Young tableaux of size n with all rows and columns weakly increasing and all regions non-singleton skew-partitions. 2
 1, 0, 2, 3, 13, 32, 121, 376, 1406, 5030, 19632, 76334, 314582, 1308550, 5667494, 24940458, 113239394, 523149560, 2480434938, 11968944532, 59051754824 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS A generalized Young tableau of shape y is an array obtained by replacing the dots in the Ferrers diagram of y with positive integers. A tableau is normal if its entries span an initial interval of positive integers. LINKS EXAMPLE The a(4) = 13 tableaux: 1 1 2 2   1 1 1 1 . 1 2 2   1 1 2   1 1 1 1       2       1 . 1 2   1 1   1 1 1 2   2 2   1 1 . 1 2  1 1   1 1 1    2     1 2    2     1 . 1   1 1   1 2   1 2   1 MATHEMATICA undptns[y_]:=DeleteCases[Select[Tuples[Range[0, #]&/@y], OrderedQ[#, GreaterEqual]&], 0, {2}]; ehn[y_]:=ehn[y]=If[Total[y]=!=1, 1, 0]+Sum[ehn[c], {c, Select[undptns[y], Total[#]>1&&Total[y]-Total[#]>1&]}]; Table[Sum[ehn[y], {y, IntegerPartitions[n]}], {n, 15}] CROSSREFS Cf. A000085, A063834, A138178, A153452, A238690, A296188, A297388, A299925, A299926, A299966. Sequence in context: A072997 A037428 A073688 * A216359 A169983 A151461 Adjacent sequences:  A299964 A299965 A299966 * A299968 A299969 A299970 KEYWORD nonn,more AUTHOR Gus Wiseman, Feb 22 2018 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 December 14 09:41 EST 2019. Contains 329979 sequences. (Running on oeis4.)