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%I #35 Oct 20 2019 10:25:25
%S 1,3,3,5,5,5,7,7,7,7,9,9,9,9,9,11,11,11,11,11,11,13,13,13,13,13,13,13,
%T 15,15,15,15,15,15,15,15,17,17,17,17,17,17,17,17,17,19,19,19,19,19,19,
%U 19,19,19,19,21,21,21,21,21,21,21,21,21,21,21,23,23,23,23,23,23,23,23,23,23,23,23
%N 2n+1 appears n+1 times.
%C Sum of terms of row n is (n+1)*(2n+1) = A000384(n+1). - _Michel Marcus_, Feb 02 2014
%C Where records occur give A000217. - _Omar E. Pol_, Nov 05 2015
%H Reinhard Zumkeller, <a href="/A131507/b131507.txt">Rows n = 0..125 of triangle, flattened</a>
%F a(n) = 2*floor(sqrt(2n+1)+1/2) - 1. - _Ridouane Oudra_, Oct 20 2019
%e As a triangle, the sequence starts:
%e 1;
%e 3, 3;
%e 5, 5, 5;
%e 7, 7, 7, 7;
%e 9, 9, 9, 9, 9;
%e ...
%p seq(2*floor(sqrt(2*n+1)+1/2)-1, n=0..70); # _Ridouane Oudra_, Oct 20 2019
%t Table[2 n + 1, {n, 0, 11}, {n + 1}] // Flatten (* _Michael De Vlieger_, Nov 05 2015 *)
%o (Haskell)
%o a131507 n k = a131507_tabl !! n !! k
%o a131507_row n = a131507_tabl !! n
%o a131507_tabl = zipWith ($) (map replicate [1..]) [1, 3 ..]
%o a131507_list = concat a131507_tabl
%o -- _Reinhard Zumkeller_, Jul 12 2014, Mar 18 2011
%o (Chipmunk BASIC v3.6.4(b8)) # http://www.nicholson.com/rhn/basic/
%o for n=1 to 23 step 2
%o for j=1 to n step 2
%o print str$(n)+", ";
%o next j : next n : print
%o end
%o # _Jeremy Gardiner_, Feb 02 2014
%Y Cf. A000217, A002024, A003056, A005408.
%Y Cf. A001650.
%K nonn,tabl
%O 0,2
%A _Paul Curtz_, Aug 13 2007
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