cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A210947 Triangle read by rows: T(n,k) = total number of parts <= k of all partitions of n.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 12, 16, 18, 19, 20, 19, 27, 31, 33, 34, 35, 30, 41, 47, 50, 52, 53, 54, 45, 64, 73, 79, 82, 84, 85, 86, 67, 93, 108, 116, 121, 124, 126, 127, 128, 97, 138, 159, 172, 180, 185, 188, 190, 191, 192
Offset: 1

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Author

Omar E. Pol, May 01 2012

Keywords

Comments

Row n lists the partial sums of row n of triangle A066633.

Examples

			Triangle begins:
1;
2,   3;
4,   5,  6;
7,  10,  11,  12;
12, 16,  18,  19,  20;
19, 27,  31,  33,  34,  35;
30, 41,  47,  50,  52,  53,  54;
45, 64,  73,  79,  82,  84,  85,  86;
67, 93, 108, 116, 121, 124, 126, 127, 128;
		

Crossrefs

Column 1 is A000070(n-1). Right border gives A006128.

Programs

  • Maple
    p:= (f, g)-> zip((x, y)-> x+y, f, g, 0):
    b:= proc(n, i) option remember; local f, g;
          if n=0 then [1]
        elif i=1 then [1, n]
        else f:= b(n, i-1); g:= `if`(i>n, [0], b(n-i, i));
             p (p (f, g), [0$i, g[1]])
          fi
        end:
    T:= proc(n, k) option remember;
           b(n, n)[k+1] +`if`(k<2, 0, T(n, k-1))
        end:
    seq (seq (T(n,k), k=1..n), n=1..11); # Alois P. Heinz, May 02 2012
  • Mathematica
    p[f_, g_] := With[{m = Max[Length[f], Length[g]]}, PadRight[f, m, 0] + PadRight[g, m, 0]]; b[n_, i_] := b[n, i] = Module[{f, g}, If[n == 0, {1}, If[i == 1, {1, n}, f = b[n, i-1]; g = If[i>n, {0}, b[n-i, i]]; p[p[f, g], Append[Array[0&, i], g[[1]] ]]]]]; T[n_, k_] := T[n, k] = b[n, n][[k+1]] + If[k<2, 0, T[n, k-1]]; Table [Table [T[n, k], {k, 1, n}], {n, 1, 11}] // Flatten (* Jean-François Alcover, Mar 11 2015, after Alois P. Heinz *)

Formula

T(n,k) = Sum_{j=1..k} A066633(n,j).