A270529 -id:A270529 - cp's OEIS frontend

A270236 Triangle T(n,p) read by rows: the number of occurrences of p in the restricted growth functions of length n.

1, 3, 1, 9, 5, 1, 30, 21, 8, 1, 112, 88, 47, 12, 1, 463, 387, 253, 97, 17, 1, 2095, 1816, 1345, 675, 184, 23, 1, 10279, 9123, 7304, 4418, 1641, 324, 30, 1, 54267, 48971, 41193, 28396, 13276, 3645, 536, 38, 1, 306298, 279855, 243152, 183615, 102244, 36223, 7473, 842, 47, 1

Offset: 1

R. J. Mathar, Mar 13 2016

The RG functions used here are defined by f(1)=1, f(j) <= 1+max_{i

T(n,p) is the number of elements in the p-th subset in all set partitions of [n]. - Joerg Arndt, Mar 14 2016

			The two restricted growth functions of length 2 are (1,1) and (1,2). The 1 appears 3 times and the 2 once, so T(2,1)=3 and T(2,2)=1.
1;
3,1;
9,5,1;
30,21,8,1;
112,88,47,12,1;
463,387,253,97,17,1;
2095,1816,1345,675,184,23,1;
10279,9123,7304,4418,1641,324,30,1;
54267,48971,41193,28396,13276,3645,536,38,1;
306298,279855,243152,183615,102244,36223,7473,842,47,1;
1838320,1695902,1506521,1211936,770989,334751,90223,14303,1267,57,1;
11677867,10856879,9799547,8237223,5795889,2965654,995191,207186,25820, 1839,68,1;

Alois P. Heinz, Rows n = 1..141, flattened

Cf. A070071 (row sums).
Column p=1-10 gives: A124427, A270494, A270495, A270496, A270497, A270498, A270499, A270500, A270501, A270502.
T(2n+1,n+1) gives A270529.
Cf. A000110, A185105, A285362, A286416, A346772.

b:= proc(n, m) option remember; `if`(n=0, [1, 0], add((p->
      [p[1], p[2]+p[1]*x^j])(b(n-1, max(m, j))), j=1..m+1))
    end:
T:= n-> (p-> seq(coeff(p, x, i), i=1..n))(b(n, 0)[2]):
seq(T(n), n=0..12);  # Alois P. Heinz, Mar 14 2016

b[n_, m_] := b[n, m] = If[n == 0, {1, 0}, Sum[Function[p, {p[[1]], p[[2]] + p[[1]]*x^j}][b[n-1, Max[m, j]]], {j, 1, m+1}]];
T[n_] := Function[p, Table[Coefficient[p, x, i], {i, 1, n}]][b[n, 0][[2]] ]; Table[T[n], {n, 0, 12}] // Flatten (* Jean-François Alcover, Apr 07 2016, after Alois P. Heinz *)

T(n,n) = 1.
Conjecture: T(n,n-1) = 2+n*(n-1)/2 for n>1.
Conjecture: T(n+1,n-1) = 2+n*(n+1)*(3*n^2-5*n+26)/24 for n>1.
Sum_{k=1..n} k * T(n,k) = A346772(n). - Alois P. Heinz, Aug 03 2021

A285410 Sum of the entries in the (n+1)-th blocks of all set partitions of [2n+1].

Original entry on oeis.org

1, 12, 185, 3757, 96454, 3018824, 111964040, 4813480830, 235727269842, 12967143328027, 792113203502422, 53224214308284463, 3902445739220008603, 310108348556403600064, 26551900616231571763742, 2437107937223749442138164, 238735439946016510599661488

Offset: 0

Alois P. Heinz, Apr 18 2017

nonn

			a(1) = 12 because the sum of the entries in the second blocks of all set partitions of [3] (123, 12|3, 13|2, 1|23, 1|2|3) is 0+3+2+5+2 = 12.

Alois P. Heinz, Table of n, a(n) for n = 0..345
Wikipedia, Partition of a set

Cf. A270529, A285362.

a:= proc(h) option remember; local b; b:=
      proc(n, m) option remember;
        `if`(n=0, [1, 0], add((p-> `if`(j=h+1, p+ [0,
        (2*h-n+2)*p[1]], p))(b(n-1, max(m, j))), j=1..m+1))
      end: b(2*h+1, 0)[2]
    end:
seq(a(n), n=0..20);

a[h_] := a[h] = Module[{b}, b[0, ] = {1, 0}; b[n, m_] := b[n, m] = Sum[ If[j == h + 1, # + {0, (2*h - n + 2)*#[[1]]}, #]&[b[n - 1, Max[m, j]]], {j, 1, m + 1}]; b[2*h + 1, 0][[2]]];
Table[a[n], {n, 0, 20}] (* Jean-François Alcover, May 23 2018, translated from Maple *)

a(n) = A285362(2n+1,n+1).

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A270236 Triangle T(n,p) read by rows: the number of occurrences of p in the restricted growth functions of length n.

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