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A238354 Triangle T(n,k) read by rows: T(n,k) is the number of partitions of n (as weakly ascending list of parts) with minimal ascent k, n >= 0, 0 <= k <= n.

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%I A238354 #29 May 20 2025 08:31:07
%S A238354 1,1,0,2,0,0,2,1,0,0,4,0,1,0,0,5,1,0,1,0,0,8,1,1,0,1,0,0,11,2,0,1,0,1,
%T A238354 0,0,17,2,1,0,1,0,1,0,0,23,3,1,1,0,1,0,1,0,0,33,4,2,0,1,0,1,0,1,0,0,
%U A238354 45,5,2,1,0,1,0,1,0,1,0,0,63,6,3,1,1,0,1,0,1,0,1,0,0,84,8,3,2,0,1,0,1,0,1,0,1,0,0,114,10,4,2,1,0,1,0,1,0,1,0,1,0,0
%N A238354 Triangle T(n,k) read by rows: T(n,k) is the number of partitions of n (as weakly ascending list of parts) with minimal ascent k, n >= 0, 0 <= k <= n.
%C A238354 Column k=0: T(n,0) = 1 + A047967(n).
%C A238354 Column k=1 is A238708.
%C A238354 Row sums are A000041.
%H A238354 Joerg Arndt and Alois P. Heinz, <a href="/A238354/b238354.txt">Rows n = 0..140, flattened</a>
%e A238354 Triangle starts:
%e A238354   00:    1;
%e A238354   01:    1,  0;
%e A238354   02:    2,  0, 0;
%e A238354   03:    2,  1, 0, 0;
%e A238354   04:    4,  0, 1, 0, 0;
%e A238354   05:    5,  1, 0, 1, 0, 0;
%e A238354   06:    8,  1, 1, 0, 1, 0, 0;
%e A238354   07:   11,  2, 0, 1, 0, 1, 0, 0;
%e A238354   08:   17,  2, 1, 0, 1, 0, 1, 0, 0;
%e A238354   09:   23,  3, 1, 1, 0, 1, 0, 1, 0, 0;
%e A238354   10:   33,  4, 2, 0, 1, 0, 1, 0, 1, 0, 0;
%e A238354   11:   45,  5, 2, 1, 0, 1, 0, 1, 0, 1, 0, 0;
%e A238354   12:   63,  6, 3, 1, 1, 0, 1, 0, 1, 0, 1, 0, 0;
%e A238354   13:   84,  8, 3, 2, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0;
%e A238354   14:  114, 10, 4, 2, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0;
%e A238354   15:  150, 13, 4, 3, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0;
%e A238354   ...
%e A238354 The 11 partitions of 6 together with their minimal ascents are:
%e A238354   01:  [ 1 1 1 1 1 1 ]   0
%e A238354   02:  [ 1 1 1 1 2 ]     0
%e A238354   03:  [ 1 1 1 3 ]       0
%e A238354   04:  [ 1 1 2 2 ]       0
%e A238354   05:  [ 1 1 4 ]         0
%e A238354   06:  [ 1 2 3 ]         1
%e A238354   07:  [ 1 5 ]           4
%e A238354   08:  [ 2 2 2 ]         0
%e A238354   09:  [ 2 4 ]           2
%e A238354   10:  [ 3 3 ]           0
%e A238354   11:  [ 6 ]             0
%e A238354 There are 8 partitions of 6 with min ascent 0, 1 with min ascents 1, 2, and 4, giving row 6 of the triangle: 8, 1, 1, 0, 1, 0, 0.
%p A238354 b:= proc(n, i, t) option remember; `if`(n=0, 1/x, `if`(i<1, 0,
%p A238354       b(n, i-1, t)+`if`(i>n, 0, (p->`if`(t=0, p, add(coeff(
%p A238354        p, x, j)*x^`if`(j<0, t-i, min(j, t-i)),
%p A238354        j=-1..degree(p))))(b(n-i, i, i)))))
%p A238354     end:
%p A238354 T:= n->(p->seq(coeff(p, x, k)+`if`(k=0, 1, 0), k=0..n))(b(n$2, 0)):
%p A238354 seq(T(n), n=0..15);
%t A238354 b[n_, i_, t_] := b[n, i, t] = If[n == 0, 1/x, If[i<1, 0, b[n, i-1, t]+If[i>n, 0, Function[{p}, If[t == 0, p, Sum[Coefficient[p, x, j]*x^If[j<0, t-i, Min[j, t-i]], {j, -1, Exponent[p, x]}]]][b[n-i, i, i]]]]]; T[n_] := Function[{p}, Table[ Coefficient[p, x, k]+If[k == 0, 1, 0], {k, 0, n}]][b[n, n, 0]]; Table[T[n], {n, 0, 15}] // Flatten (* _Jean-François Alcover_, Jan 12 2015, translated from Maple *)
%Y A238354 Cf. A238353 (partitions by maximal ascent).
%K A238354 nonn,tabl
%O A238354 0,4
%A A238354 _Joerg Arndt_ and _Alois P. Heinz_, Feb 26 2014