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A129994
Triangle read by rows: 2*A007318 - I.
1
1, 2, 1, 2, 4, 1, 2, 6, 6, 1, 2, 8, 12, 8, 1, 2, 10, 20, 20, 10, 1, 2, 12, 30, 40, 30, 12, 1, 2, 14, 42, 70, 70, 42, 14, 1, 2, 16, 56, 112, 140, 112, 56, 16, 1, 2, 18, 72, 168, 252, 252, 168, 72, 18, 1
OFFSET
0,2
COMMENTS
Row sums = (1, 3, 7, 15, 31, ...).
FORMULA
Let Pascal's triangle A007318 = P, then this is 2*P - I, I = Identity matrix.
EXAMPLE
First few rows of the triangle are:
1;
2, 1;
2, 4, 1;
2, 6, 6, 1;
2, 8, 12, 8, 1;
2, 10, 20, 20, 10, 1;
2, 12, 30, 40, 30, 12, 1;
...
MATHEMATICA
Table[2 Binomial[n, k] - Boole[k == n], {n, 0, 9}, {k, 0, n}] // Flatten (* Michael De Vlieger, Nov 02 2017 *)
CROSSREFS
Cf. A007318.
Sequence in context: A203647 A376826 A114791 * A208755 A226441 A080246
KEYWORD
nonn,tabl
AUTHOR
Gary W. Adamson, Jun 15 2007
EXTENSIONS
Name corrected by Peter Bala, Nov 02 2017
STATUS
approved