

A238892


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


2



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
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OFFSET

0,5


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


MATHEMATICA

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


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).
Sequence in context: A131704 A124492 A057646 * A238279 A282933 A052275
Adjacent sequences: A238889 A238890 A238891 * A238893 A238894 A238895


KEYWORD

nonn


AUTHOR

T. D. Noe, Mar 06 2014


STATUS

approved



