

A014462


Triangular array formed from elements to left of middle of Pascal's triangle.


7



1, 1, 1, 3, 1, 4, 1, 5, 10, 1, 6, 15, 1, 7, 21, 35, 1, 8, 28, 56, 1, 9, 36, 84, 126, 1, 10, 45, 120, 210, 1, 11, 55, 165, 330, 462, 1, 12, 66, 220, 495, 792, 1, 13, 78, 286, 715, 1287, 1716, 1, 14, 91, 364, 1001, 2002, 3003, 1, 15, 105, 455, 1365, 3003, 5005, 6435, 1, 16
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OFFSET

1,4


COMMENTS

Coefficients for Pontryagin classe of projective spaces. See p. 3 of the Wilson link. Aerated to become a lower triangular matrix with alternating zeros on the diagonal, this matrix appparently becomes the reverse, or mirror, of A117178.  Tom Copeland, May 30 2017


LINKS

Reinhard Zumkeller, Rows n = 1..200 of triangle, flattened
D. Wilson, Genera: From cobordism to Ktheory, Jul 2016.
Index entries for triangles and arrays related to Pascal's triangle


EXAMPLE

1;
1;
1, 3;
1, 4;
1, 5, 10;
1, 6, 15;
1, 7, 21, 35;
1, 8, 28, 56;
1, 9, 36, 84, 126;
1, 10, 45, 120, 210;
1, 11, 55, 165, 330, 462;


PROG

(Haskell)
a014462 n k = a014462_tabf !! (n1) !! (k1)
a014462_row n = a014462_tabf !! (n1)
a014462_tabf = map reverse a014413_tabf
 Reinhard Zumkeller, Dec 24 2015


CROSSREFS

Cf. A014413, A034868, A058622 (row sums).
Cf. A001791 (a halfdiagonal and diagonal sums).
Cf. A007318.
Cf. A117178.
Sequence in context: A057466 A187079 A086183 * A309992 A016474 A332678
Adjacent sequences: A014459 A014460 A014461 * A014463 A014464 A014465


KEYWORD

tabf,nonn,easy


AUTHOR

Mohammad K. Azarian


EXTENSIONS

More terms from James A. Sellers


STATUS

approved



