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A134403 Triangle read by rows: row n consists of (n, n, (n+1), (n+2), (n+3), ...).

%I A134403 #12 Feb 08 2022 19:48:11
%S A134403 0,1,1,2,2,3,3,3,4,5,4,4,5,6,7,5,5,6,7,8,9,6,6,7,8,9,10,11,7,7,8,9,10,
%T A134403 11,12,13,8,8,9,10,11,12,13,14,15,9,9,10,11,12,13,14,15,16,17,10,10,
%U A134403 11,12,13,14,15,16,17,18,19,11,11,12,13,14,15,16
%N A134403 Triangle read by rows: row n consists of (n, n, (n+1), (n+2), (n+3), ...).
%C A134403 Row sums = A005449: (0, 2, 7, 15, 26, 40, 57, ...).
%H A134403 Harvey P. Dale, <a href="/A134403/b134403.txt">Table of n, a(n) for n = 0..1000</a>
%F A134403 Equals (A000012 * A134402 + A134402 * A000012) - A000012.
%e A134403 First few rows of the triangle:
%e A134403   0;
%e A134403   1, 1;
%e A134403   2, 2, 3;
%e A134403   3, 3, 4, 5;
%e A134403   4, 4, 5, 6,  7;
%e A134403   5, 5, 6, 7,  8,  9;
%e A134403   6, 6, 7, 8,  9, 10, 11;
%e A134403   7, 7, 8, 9, 10, 11, 12, 13;
%e A134403   ...
%t A134403 Table[{n,n+Range[0,n-1]},{n,0,20}]//Flatten (* _Harvey P. Dale_, Dec 26 2020 *)
%Y A134403 Cf. A134402, A005449.
%K A134403 nonn,tabl
%O A134403 0,4
%A A134403 _Gary W. Adamson_, Oct 23 2007
%E A134403 Leading term changed from 1 to 0 by _N. J. A. Sloane_, Apr 06 2008
%E A134403 Corrected and extended by _Harvey P. Dale_, Dec 26 2020