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.

A179902 Row sums of triangle A179901.

Original entry on oeis.org

1, 2, 5, 11, 23, 46, 87, 155, 261, 416, 641, 947, 1355, 1886
Offset: 1

Views

Author

Gary W. Adamson, Jul 31 2010

Keywords

Comments

Conjectured mod 2 parity: (1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1,...)

Examples

			a(5) = 23 = sum of 5th row terms of triangle A179901: (1, + 4, + 6 + 8 + 4).
		

Crossrefs

Cf. A179901.

Formula

Row sums of triangle A179901

A179000 Array T(n,k) read by antidiagonals: coefficient [x^k] of (1 + n*Sum_{i>=1} x^i)^2, k >= 0.

Original entry on oeis.org

1, 1, 2, 1, 4, 3, 1, 6, 8, 4, 1, 8, 15, 12, 5, 1, 10, 24, 24, 16, 6, 1, 12, 35, 40, 33, 20, 7, 1, 14, 48, 60, 56, 42, 24, 8, 1, 16, 63, 84, 85, 72, 51, 28, 9, 1, 18, 80, 112, 120, 110, 88, 60, 32, 10
Offset: 1

Views

Author

Gary W. Adamson, Jan 03 2011

Keywords

Comments

Antidiagonal sums are in A136396.

Examples

			First few rows of the array:
  1   2   3   4   5   6   7   8   9  10  11  A000027
  1   4   8  12  16  20  24  28  32  36  40  A008574
  1   6  15  24  33  42  51  60  69  78  87  A122709
  1   8  24  40  56  72  88 104 120 136 152  A051062
  1  10  35  60  85 110 135 160 185 210 235
  1  12  48  84 120 156 192 228 264 300 336
  1  14  63 112 161 210 259 308 357 406 455
  1  16  80 144 208 272 336 400 464 528 592
  1  18  99 180 261 342 423 504 585 666 747
Row n=3 is generated by (1 + 3x + 3x^2 + 3x^3 + 3x^4 + ...)^2 = 1 + 6x + 15x^2 + 24x^3 + ..., for example.
		

Crossrefs

Programs

  • Maple
    A179000 := proc(n,k) if k = 0 then 1; else 2*n+n^2*(k-1) ; end if; end proc: # R. J. Mathar, Jan 05 2011

Formula

T(n,0) = 1; T(n,k) = n*(2+n*(k-1)), k > 0. - R. J. Mathar, Jan 05 2011
Showing 1-2 of 2 results.