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A275071
Number of set partitions of [n] such that i-j is a multiple of four for all i,j belonging to the same block.
2
1, 1, 1, 1, 1, 2, 4, 8, 16, 40, 100, 250, 625, 1875, 5625, 16875, 50625, 175500, 608400, 2109120, 7311616, 28543424, 111429136, 435002204, 1698181681, 7336479479, 31695036961, 136928804999, 591559418641, 2792538190620, 13182563408400, 62230116888000
OFFSET
0,6
LINKS
FORMULA
a(n) = Product_{i=0..3} A000110(floor((n+i)/4)).
EXAMPLE
a(9) = 40: 159|26|37|48, 15|26|37|48|9, 159|26|37|4|8, 15|26|37|4|8|9, 159|26|3|48|7, 15|26|3|48|7|9, 159|26|3|4|7|8, 15|26|3|4|7|8|9, 159|2|37|48|6, 15|2|37|48|6|9, 159|2|37|4|6|8, 15|2|37|4|6|8|9, 159|2|3|48|6|7, 15|2|3|48|6|7|9, 159|2|3|4|6|7|8, 15|2|3|4|6|7|8|9, 19|26|37|48|5, 1|26|37|48|59, 1|26|37|48|5|9, 19|26|37|4|5|8, 1|26|37|4|59|8, 1|26|37|4|5|8|9, 19|26|3|48|5|7, 1|26|3|48|59|7, 1|26|3|48|5|7|9, 19|26|3|4|5|7|8, 1|26|3|4|59|7|8, 1|26|3|4|5|7|8|9, 19|2|37|48|5|6, 1|2|37|48|59|6, 1|2|37|48|5|6|9, 19|2|37|4|5|6|8, 1|2|37|4|59|6|8, 1|2|37|4|5|6|8|9, 19|2|3|48|5|6|7, 1|2|3|48|59|6|7, 1|2|3|48|5|6|7|9, 19|2|3|4|5|6|7|8, 1|2|3|4|59|6|7|8, 1|2|3|4|5|6|7|8|9.
CROSSREFS
Column k=4 of A275069.
Cf. A000110.
Sequence in context: A350495 A337581 A259377 * A018575 A013116 A012912
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Jul 15 2016
STATUS
approved