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A074147
(2n-1) odd numbers followed by 2n even numbers.
15
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
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 A372341 A166014
KEYWORD
nonn,easy,tabl
AUTHOR
Amarnath Murthy, Aug 28 2002
STATUS
approved