OFFSET
0,2
COMMENTS
2*n appears n+1 times in row n.
EXAMPLE
Triangle begins:
0;
2, 2;
4, 4, 4;
6, 6, 6, 6;
8, 8, 8, 8, 8;
10, 10, 10, 10, 10, 10;
12, 12, 12, 12, 12, 12, 12;
14, 14, 14, 14, 14, 14, 14, 14;
16, 16, 16, 16, 16, 16, 16, 16, 16;
18, 18, 18, 18, 18, 18, 18, 18, 18, 18;
20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20;
22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22;
...
MATHEMATICA
Table[ConstantArray[2 n, n + 1], {n, 0, 11}] // Flatten (* Michael De Vlieger, Dec 22 2016 *)
Table[#, #/2+1]&/@(2*Range[0, 20])//Flatten(* Harvey P. Dale, Oct 09 2018 *)
PROG
(PARI) row(n) = vector(n, x, 2*(n-1))
trianglerows(n) = for(k=1, n, print(row(k)))
/* Print initial 12 rows of triangle as follows: */
trianglerows(12) \\ Felix Fröhlich, Dec 22 2016
CROSSREFS
KEYWORD
AUTHOR
Omar E. Pol, Dec 22 2016
STATUS
approved