A074147 (2n-1) odd numbers followed by 2n even numbers.

1, 2, 4, 3, 5, 7, 6, 8, 10, 12, 9, 11, 13, 15, 17, 14, 16, 18, 20, 22, 24, 19, 21, 23, 25, 27, 29, 31, 26, 28, 30, 32, 34, 36, 38, 40, 33, 35, 37, 39, 41, 43, 45, 47, 49, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 62, 64, 66, 68, 70, 72

Offset

1,2

Links

Ivan Neretin, Table of n, a(n) for n = 1..5050

Formula

T(n,k) = A061925(n-1)+2k, 0<=k<n. - R. J. Mathar, Jul 17 2007, corrected Nov 02 2023

a(n) = A116941(n-1)+1. - Robert G. Wilson v, Mar 09 2017

Example

As a triangular array:
1,
2, 4,
3, 5, 7,
6, 8, 10, 12,
9, 11, 13, 15, 17,
14, 16, 18, 20, 22, 24,
...

Maple

A074147 := proc(n, k)
    ceil((n-1)^2/2)+1+2*k ;
end proc:
seq(seq( A074147(n, k), k=0..n-1) , n=1..12) ; # R. J. Mathar, Nov 02 2023

Mathematica

Flatten@Table[Ceiling[(n - 1)^2/2] + 2 k - 1, {n, 12}, {k, n}] (* Ivan Neretin, Dec 15 2016 *)

Crossrefs

Cf. A074148, A074149 (row sums), A001614.

Sequence in context: A262478 A236348 A143097 * A138607 A166014 A357527

Adjacent sequences: A074144 A074145 A074146 * A074148 A074149 A074150

Keyword

nonn,easy,tabl

Author

Amarnath Murthy, Aug 28 2002

Status

approved