A238892 Index of last squarefree number in the first half of row n of Pascal's triangle.

0, 0, 1, 1, 2, 2, 2, 3, 4, 0, 4, 5, 2, 4, 6, 6, 0, 8, 0, 9, 8, 9, 10, 11, 4, 5, 10, 0, 10, 11, 2, 10, 0, 1, 16, 3, 0, 4, 18, 18, 4, 9, 10, 18, 20, 12, 18, 20, 0, 0, 0, 1, 16, 21, 18, 10, 0, 21, 22, 23, 28, 29, 30, 9, 0, 1, 2, 3, 32, 33, 6, 35, 0, 9, 32, 10, 36

Offset: 0

Author

T. D. Noe, Mar 06 2014

Keywords

• nonn

Comments

The first squarefree binomial coefficient in every row is at position 0. Sequence A048279 lists the rows n for which a(n) = 0.

Links

• T. D. Noe, Table of n, a(n) for n = 0..10000

Crossrefs

Cf. A048279 (positions of zeros).

Cf. A238337 (number of distinct squarefree numbers in row n).

Cf. A238891 (last squarefree number in the first half of row n).

Programs

Mathematica

Table[Position[Binomial[n, Range[0, n/2]], _?(SquareFreeQ[#] &)][[-1,1]] - 1, {n, 0, 100}]