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A133091
2
1, 2, 2, 1, 2, 3, 2, 4, 6, 4, 1, 2, 3, 4, 5, 2, 4, 6, 8, 10, 6, 1, 2, 3, 4, 5, 6, 7, 2, 4, 6, 8, 10, 12, 14, 8, 1, 2, 3, 4, 5, 6, 7, 8, 9, 2, 4, 6, 8, 10, 12, 14, 16, 18, 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 2
OFFSET
1,2
COMMENTS
Row sums = A133092: (1, 4, 6, 16, 15, 36, 28, ...).
FORMULA
A133080 * A002260 as infinite lower triangular matrices.
Odd n rows = (1,2,3,...,n). Even n rows = (2,4,6,...,n).
EXAMPLE
First few rows of the triangle:
1;
2, 2;
1, 2, 3;
2, 4, 6, 4;
1, 2, 3, 4, 5;
2, 4, 6, 8, 10, 6;
1, 2, 3, 4, 5, 6, 7;
...
MATHEMATICA
T[n_, n_] := n; T[n_, k_] := (2 - (1 - (-1)^n)/2)*k; Table[T[n, k], {n, 1, 10}, {k, 1, n}] (* G. C. Greubel, Oct 21 2017 *)
PROG
(PARI) for(n=1, 10, for(k=1, n, print1(if(k==n, n, (2 - (1 - (-1)^n)/2)*k), ", "))) \\ G. C. Greubel, Oct 21 2017
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Gary W. Adamson, Sep 09 2007
EXTENSIONS
Corrected and extended by Philippe Deléham, Mar 02 2012
STATUS
approved