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 A285924 Number of ordered set partitions of [n] into nine blocks such that equal-sized blocks are ordered with increasing least elements. 3
 1, 405, 37125, 1738935, 64914993, 1775214441, 38186115825, 751359827790, 13076544824343, 207877406991111, 3041686131983343, 41512373437449915, 544051964769008601, 6850772610392201733, 82608610920666732693, 956263706215482795570, 10851693841665124551180 (list; graph; refs; listen; history; text; internal format)
 OFFSET 9,2 LINKS Alois P. Heinz, Table of n, a(n) for n = 9..700 Wikipedia, Partition of a set MAPLE b:= proc(n, i, p) option remember; series(`if`(n=0 or i=1, (p+n)!/n!*x^n, add(x^j*b(n-i*j, i-1, p+j)*combinat [multinomial](n, n-i*j, i\$j)/j!^2, j=0..n/i)), x, 10) end: a:= n-> coeff(b(n\$2, 0), x, 9): seq(a(n), n=9..30); MATHEMATICA multinomial[n_, k_List] := n!/Times @@ (k!); b[n_, i_, p_] := b[n, i, p] = Series[If[n == 0 || i == 1, (p + n)!/n!*x^n, Sum[x^j*b[n - i*j, i - 1, p + j]*multinomial[n, Join[{n - i*j}, Table[i, j]]]/j!^2, {j, 0, n/i}]], {x, 0, 10}]; a[n_] := Coefficient[b[n, n, 0], x, 9]; Table[a[n], {n, 9, 30}] (* Jean-François Alcover, May 17 2018, translated from Maple *) CROSSREFS Column k=9 of A285824. Cf. A285860. Sequence in context: A239541 A187134 A185839 * A285860 A151634 A132362 Adjacent sequences: A285921 A285922 A285923 * A285925 A285926 A285927 KEYWORD nonn AUTHOR Alois P. Heinz, Apr 28 2017 STATUS approved

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Last modified December 9 13:48 EST 2023. Contains 367691 sequences. (Running on oeis4.)