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

%I A074147 #20 Nov 02 2023 07:48:33
%S A074147 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,
%T A074147 29,31,26,28,30,32,34,36,38,40,33,35,37,39,41,43,45,47,49,42,44,46,48,
%U A074147 50,52,54,56,58,60,51,53,55,57,59,61,63,65,67,69,71,62,64,66,68,70,72
%N A074147 (2n-1) odd numbers followed by 2n even numbers.
%H A074147 Ivan Neretin, <a href="/A074147/b074147.txt">Table of n, a(n) for n = 1..5050</a>
%F A074147 T(n,k) = A061925(n-1)+2k, 0<=k<n. - _R. J. Mathar_, Jul 17 2007, corrected Nov 02 2023
%F A074147 a(n) = A116941(n-1)+1. - _Robert G. Wilson v_, Mar 09 2017
%e A074147 As a triangular array:
%e A074147 1,
%e A074147 2, 4,
%e A074147 3, 5, 7,
%e A074147 6, 8, 10, 12,
%e A074147 9, 11, 13, 15, 17,
%e A074147 14, 16, 18, 20, 22, 24,
%e A074147 ...
%p A074147 A074147 := proc(n,k)
%p A074147     ceil((n-1)^2/2)+1+2*k ;
%p A074147 end proc:
%p A074147 seq(seq( A074147(n,k),k=0..n-1) ,n=1..12) ; # _R. J. Mathar_, Nov 02 2023
%t A074147 Flatten@Table[Ceiling[(n - 1)^2/2] + 2 k - 1, {n, 12}, {k, n}] (* _Ivan Neretin_, Dec 15 2016 *)
%Y A074147 Cf. A074148, A074149 (row sums), A001614.
%K A074147 nonn,easy,tabl
%O A074147 1,2
%A A074147 _Amarnath Murthy_, Aug 28 2002