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A134235
Triangle read by rows: a(1) = 1; then n-th row = n terms of (n+2), (n+4), (n+6), ..., n.
0
1, 4, 2, 5, 7, 3, 6, 8, 10, 4, 7, 9, 11, 13, 5, 8, 10, 12, 14, 16, 6, 9, 11, 13, 15, 17, 19, 7, 10, 12, 14, 16, 18, 20, 22, 8, 11, 13, 15, 17, 19, 21, 23, 25, 9, 12, 14, 16, 18, 20, 22, 24, 26, 28, 10
OFFSET
1,2
COMMENTS
Row sums = the hexagonal numbers, A000384: (1, 6, 15, 28, 45, 66, 91, ...).
EXAMPLE
First few rows of the triangle:
1;
4, 2;
5, 7, 3;
6, 8, 10, 4;
7, 9, 11, 13, 5;
8, 10, 12, 14, 16, 6;
9, 11, 13, 15, 17, 19, 7;
...
CROSSREFS
Cf. A000384.
Sequence in context: A260623 A199625 A020849 * A266626 A159979 A198233
KEYWORD
nonn,tabl
AUTHOR
Gary W. Adamson, Oct 14 2007
STATUS
approved