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A048195 Numbers k for which binomial(k, floor(k/2)) has fewer unitary than non-unitary divisors. 0
10, 25, 26, 27, 28, 29, 30, 34, 36, 37, 38, 40, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 58, 60, 61, 62, 63, 64, 66, 68, 69, 70, 75, 76, 77, 78, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 108, 109, 110 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

A048111 applied to central binomial coefficients.

LINKS

Table of n, a(n) for n=1..66.

FORMULA

A034444(A001405(k)) < A048105(A001405(k)).

EXAMPLE

k=58: binomial(58,29) has 20480 divisors, 8192 unitary ones and 12288 non-unitary ones, and 8192 < 12288.

PROG

(PARI) nbud(n) = 1<<omega(n); \\ from A034444

isok(n) = my(b=binomial(n, n\2)); numdiv(b) > 2*nbud(b); \\ Michel Marcus, Mar 15 2018

CROSSREFS

Cf. A001405, A034444, A048105, A048111.

Sequence in context: A180043 A251317 A251201 * A133634 A174051 A225974

Adjacent sequences:  A048192 A048193 A048194 * A048196 A048197 A048198

KEYWORD

nonn

AUTHOR

Labos Elemer

EXTENSIONS

More terms from Michel Marcus, Mar 15 2018

STATUS

approved

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Last modified February 19 13:25 EST 2020. Contains 332044 sequences. (Running on oeis4.)