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.

A185738 Rectangular array T(n,k) = 2^n + k - 2, by antidiagonals.

Original entry on oeis.org

1, 2, 3, 3, 4, 7, 4, 5, 8, 15, 5, 6, 9, 16, 31, 6, 7, 10, 17, 32, 63, 7, 8, 11, 18, 33, 64, 127, 8, 9, 12, 19, 34, 65, 128, 255, 9, 10, 13, 20, 35, 66, 129, 256, 511, 10, 11, 14, 21, 36, 67, 130, 257, 512, 1023, 11, 12, 15, 22, 37, 68, 131, 258, 513, 1024, 2047, 12, 13, 16, 23, 38, 69, 132, 259, 514, 1025, 2048, 4095, 13, 14, 17, 24, 39, 70, 133, 260, 515, 1026, 2049, 4096, 8191, 14, 15, 18, 25, 40, 71, 134, 261, 516, 1027, 2050, 4097, 8192, 16383
Offset: 1

Views

Author

Clark Kimberling, Feb 02 2011

Keywords

Comments

This array fits in a chain: ...->(weight array)->A185738->(accumulation array->...
See the Mathematica code and A144112.

Examples

			Northwest corner:
1....2....3....4....5
3....4....5....6....7
7....8....9....10...11
15...16...17...18...19
31...32...33...34...35
		

Crossrefs

Programs

  • Mathematica
    (* This program prints the array T=A185738, the accumulation array A185739 of T, and the weight array A185740 of T. *)
    f[n_,0]:=0;f[0,k_]:=0;
    f[n_,k_]:=2^n+k-2;
    TableForm[Table[f[n,k],{n,1,10},{k,1,15}]]  (* Array A185738 *)
    Table[f[n-k+1,k],{n,14},{k,n,1,-1}]//Flatten
    s[n_,k_]:=Sum[f[i,j],{i,1,n},{j,1,k}]; (* accumulation array of {f(n,k)} *)
    FullSimplify[s[n,k]]  (* formula for accumulation array *)
    TableForm[Table[s[n,k],{n,1,10},{k,1,15}]]  (* Array A185739 *)
    Table[s[n-k+1,k],{n,14},{k,n,1,-1}]//Flatten
    w[m_,n_]:=f[m,n]+f[m-1,n-1]-f[m,n-1]-f[m-1,n]/;Or[m>0,n>0];
    TableForm[Table[w[n,k],{n,1,10},{k,1,15}]] (* Array A185740 *)
    Table[w[n-k+1,k],{n,14},{k,n,1,-1}]//Flatten

Formula

T(n,k) = 2^n + k - 2, n>=1, k>=1.

A185739 Accumulation array of A185738, by antidiagonals.

Original entry on oeis.org

1, 3, 4, 6, 10, 11, 10, 18, 25, 26, 15, 28, 42, 56, 57, 21, 40, 62, 90, 119, 120, 28, 54, 85, 128, 186, 246, 247, 36, 70, 111, 170, 258, 378, 501, 502, 45, 88, 140, 216, 335, 516, 762, 1012, 1013, 55, 108, 172, 266, 417, 660, 1030, 1530, 2035, 2036, 66, 130, 207, 320, 504, 810, 1305, 2056, 3066, 4082, 4083, 78, 154, 245, 378, 596, 966, 1587, 2590, 4106, 6138, 8177, 8178, 91
Offset: 1

Views

Author

Clark Kimberling, Feb 02 2011

Keywords

Comments

This arrays is a member of a chain; see A185738.

Examples

			Northwest corner:
1....3....6....10....15
4....10...18...28....40
11...25...42...62....85
26...56...90...128...170
		

Crossrefs

Rows 1 to 4: A000217, A028562, A140675, 2*A098847
Columns 1 to 3: A000295, A000247, A068293.

Programs

  • Mathematica
    (* See A185738 *)
    f[n_, k_] := (k/2)*(4*(2^n - 1) + (k - 3)*n);
    TableForm[Table[f[n, k], {n, 1, 10}, {k, 1, 10}]]  (* Array A185739 *)
    Table[f[n - k + 1, k], {n, 10}, {k, n, 1, -1}] // Flatten (* G. C. Greubel, Jul 11 2017 *)

Formula

T(n,k) = k*(4*(2^n-1)+(k-3)*n), k>=1, n>=1.
Showing 1-2 of 2 results.