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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 (list; graph; refs; listen; history; text; internal format)
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 K-theory, 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 !! (n-1) !! (k-1)

a014462_row n = a014462_tabf !! (n-1)

a014462_tabf = map reverse a014413_tabf

-- Reinhard Zumkeller, Dec 24 2015

CROSSREFS

Cf. A014413, A034868, A058622 (row sums).

Cf. A001791 (a half-diagonal 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

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Last modified May 31 06:22 EDT 2020. Contains 334747 sequences. (Running on oeis4.)