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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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified March 26 20:47 EDT 2019. Contains 321535 sequences. (Running on oeis4.)