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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.

A214604 Odd numbers by transposing the right half of A176271, triangle read by rows: T(n,k) = A176271(n - 1 + k, n), 1 <= k <= n.

Original entry on oeis.org

1, 5, 9, 11, 17, 25, 19, 27, 37, 49, 29, 39, 51, 65, 81, 41, 53, 67, 83, 101, 121, 55, 69, 85, 103, 123, 145, 169, 71, 87, 105, 125, 147, 171, 197, 225, 89, 107, 127, 149, 173, 199, 227, 257, 289, 109, 129, 151, 175, 201, 229, 259, 291, 325, 361, 131, 153, 177, 203, 231, 261, 293, 327, 363, 401, 441
Offset: 1

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Author

Reinhard Zumkeller, Jul 25 2012

Keywords

Examples

			.     Take the first n elements of the n-th diagonal (northeast to
.     southwest) of the triangle on the left side
.     and write this as n-th row on the triangle of the right side.
. 1:                1                    1
. 2:              _   5                  5  9
. 3:            _   9  11               11 17 25
. 4:         __  __  17  19             19 27 37 49
. 5:       __  __  25  27  29           29 39 51 65 ..
. 6:     __  __  __  37  39  41         41 53 67 .. .. ..
. 7:   __  __  __  49  51  53  55       55 69 .. .. .. .. ..
. 8: __  __  __  __  65  67  69  71     71 .. .. .. .. .. .. .. .
		

Crossrefs

Cf. A214659 (row sums), A214660 (main diagonal), A214661.

Programs

  • Haskell
    import Data.List (transpose)
    a214604 n k = a214604_tabl !! (n-1) !! (k-1)
    a214604_row n = a214604_tabl !! (n-1)
    a214604_tabl = zipWith take [1..] $ transpose a176271_tabl
    
  • Magma
    [(n+k)^2-n-3*k+1: k in [1..n], n in [1..15]]; // G. C. Greubel, Mar 10 2024
    
  • Mathematica
    Table[(n+k)^2-n-3*k+1, {n,15}, {k,n}]//Flatten (* G. C. Greubel, Mar 10 2024 *)
  • SageMath
    flatten([[(n+k)^2-n-3*k+1 for k in range(1,n+1)] for n in range(1,16)]) # G. C. Greubel, Mar 10 2024

Formula

T(n,k) = (n+k)^2 - n - 3*k + 1.
Sum_{k=1..n} T(n, k) = A214659(n).
T(2*n-1, n) = A214660(n) (main diagonal).
T(n, 1) = A028387(n-1).
T(n, n) = A016754(n-1).
T(n, k) = A214661(n,k) + 2*A025581(n,k).
T(n, k) = 2*A000290(A094727(n,k)) - A214661(n,k).