The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A274839 Number of set partitions of [n] such that the difference between each element and its block index is a multiple of six. 2
 1, 1, 1, 1, 1, 1, 1, 2, 3, 4, 5, 6, 7, 15, 30, 57, 104, 183, 310, 811, 1939, 4377, 9497, 19987, 40883, 121620, 339817, 902822, 2301883, 5665060, 13489425, 44503335, 140080438, 425111779, 1250942834, 3575716011, 9910354002, 36376567529, 127026151621 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,8 LINKS Alois P. Heinz, Table of n, a(n) for n = 0..842 Wikipedia, Partition of a set EXAMPLE a(7) = 2: 17|2|3|4|5|6, 1|2|3|4|5|6|7. a(8) = 3: 17|28|3|4|5|6, 1|28|3|4|5|6|7, 1|2|3|4|5|6|7|8. a(9) = 4: 17|28|39|4|5|6, 1|28|39|4|5|6|7, 1|2|39|4|5|6|7|8, 1|2|3|4|5|6|7|8|9. MAPLE b:= proc(n, m, t) option remember; `if`(n=0, 1,      add(`if`(irem(j-t, 6)=0, b(n-1, max(m, j),               irem(t+1, 6)), 0), j=1..m+1))     end: a:= n-> b(n, 0, 1): seq(a(n), n=0..40); MATHEMATICA b[n_, m_, t_] := b[n, m, t] = If[n == 0, 1, Sum[If[Mod[j - t, 6] == 0, b[n - 1, Max[m, j], Mod[t + 1, 6]], 0], {j, 1, m + 1}]]; a[n_] := b[n, 0, 1]; Table[a[n], {n, 0, 40}] (* Jean-François Alcover, May 15 2018, after Alois P. Heinz *) CROSSREFS Column k=6 of A274835. Sequence in context: A263469 A165804 A055402 * A065640 A264974 A334953 Adjacent sequences:  A274836 A274837 A274838 * A274840 A274841 A274842 KEYWORD nonn AUTHOR Alois P. Heinz, Jul 08 2016 STATUS approved

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

Last modified May 18 10:07 EDT 2022. Contains 353807 sequences. (Running on oeis4.)