A046531 Numerators of elements to right of central elements of 1/2-Pascal triangle (by row).

1, 1, 3, 1, 5, 1, 11, 7, 1, 9, 9, 1, 20, 27, 11, 1, 67, 19, 13, 1, 147, 105, 51, 15, 1, 126, 78, 33, 17, 1, 273, 204, 111, 83, 19, 1, 477, 315, 305, 51, 21, 1, 1023, 792, 935, 407, 123, 23, 1, 1815, 2519, 671, 265, 73, 25, 1, 3861, 6149, 3861, 936, 338, 171

Offset

1,3

Links

Table of n, a(n) for n=1..62.

Thomas M. Richardson, The three 'R's and Dual Riordan Arrays, arXiv:1609.01193 [math.CO], 2016.

Example

1/1;
1/1 1/1;                               -->  1
1/1 1/2 1/1;                           -->  1
1/1 3/2 3/2 1/1;                       -->  3  1
1/1 5/2 3/1 5/2 1/1;                   -->  5  1
1/1 7/2 11/2 11/2 7/2 1/1;             --> 11  7 1
1/1 9/2 9/1 11/1 9/1 9/2 1/1;          -->  9  9 1
1/1 11/2 27/2 20/1 20/1 27/2 11/2 1/1; --> 20 27 11 1

Crossrefs

Cf. A046213, A046226.

Sequence in context: A112031 A146285 A146059 * A289310 A160085 A147024

Adjacent sequences: A046528 A046529 A046530 * A046532 A046533 A046534

Keyword

tabf,nonn,less

Author

Mohammad K. Azarian

Extensions

More terms from Sean A. Irvine, Apr 13 2021

Status

approved