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.

Showing 1-2 of 2 results.

A210948 Triangle read by rows: T(n,k) = sum of all parts <= k of all partitions of n.

Original entry on oeis.org

1, 2, 4, 4, 6, 9, 7, 13, 16, 20, 12, 20, 26, 30, 35, 19, 35, 47, 55, 60, 66, 30, 52, 70, 82, 92, 98, 105, 45, 83, 110, 134, 149, 161, 168, 176, 67, 119, 164, 196, 221, 239, 253, 261, 270, 97, 179, 242, 294, 334, 364, 385, 401, 410, 420
Offset: 1

Views

Author

Omar E. Pol, May 01 2012

Keywords

Comments

Row n lists the partial sums of row n of triangle A138785.

Examples

			Triangle begins:
1;
2,    4;
4,    6,   9;
7,   13,  16,  20;
12,  20,  26,  30,  35;
19,  35,  47,  55,  60,  66;
30,  52,  70,  82,  92,  98, 105;
45,  83, 110, 134, 149, 161, 168, 176;
67, 119, 164, 196, 221, 239, 253, 261, 270;
		

Crossrefs

Column 1 is A000070(n-1). Right border gives A066186.

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]*i])
          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..12);  # 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}, Which[n == 0, {1}, i == 1, {1, n}, True, f = b[n, i-1]; g = If[i>n, {0}, b[n-i, i]]; p[p[f, g], Append[Array[0&, i], 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, 12 }] // Flatten (* Jean-François Alcover, Mar 11 2015, after Alois P. Heinz *)

Formula

T(n,k) = sum_{j=1..k} A138785(n,j).

A208476 Triangle read by rows: T(n,k) = total sum of odd/even parts >= k in the last section of the set of partitions of n, if k is odd/even.

Original entry on oeis.org

1, 1, 2, 5, 0, 3, 3, 8, 0, 4, 13, 2, 8, 0, 5, 13, 18, 6, 10, 0, 6
Offset: 1

Views

Author

Omar E. Pol, Feb 28 2012

Keywords

Comments

Essentially this sequence is related to A206562 in the same way as A207032 is related to A207031 and also in the same way as A206563 is related to A181187. See the calculation in the example section of A206563.

Examples

			Triangle begins:
1;
1,   2;
5,   0,  3;
3,   8,  0,  4;
13,  2,  8,  0,  5;
13, 18,  6, 10,  0,  6;
		

Crossrefs

Showing 1-2 of 2 results.