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A272880 Number of integers in [prime(n), 2*prime(n)] with maximal number of divisors. 1
1, 1, 3, 1, 3, 1, 2, 1, 1, 1, 1, 2, 2, 3, 4, 5, 6, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 3, 3, 4, 4, 4, 5, 5, 5, 5, 5, 6, 6, 6, 7, 8, 9, 9, 9, 9, 9, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Giovanni Resta, Table of n, a(n) for n = 1..10000

EXAMPLE

Let n=3, prime(n)=5. In the interval [5,10] we have 3 numbers {6,8,10} with maximal number of divisors in this interval (4).  So, a(3)=3.

MATHEMATICA

a[n_] := Tally[Sort@ DivisorSigma[0, Range[#, 2 #]&@ Prime@n]][[-1, 2]]; Array[a, 87] (* Giovanni Resta, May 08 2016 *)

PROG

(PARI) a(n) = {my(nb = 2*prime(n) - prime(n) + 1); my(vd = vector(nb, i, numdiv(prime(n)+i-1))); my(vmax = vecmax(vd)); #select(x->x == vmax, vd); } \\ Michel Marcus, May 09 2016

CROSSREFS

Cf. A272771, A272777.

Sequence in context: A128218 A010283 A134699 * A003636 A078929 A030728

Adjacent sequences:  A272877 A272878 A272879 * A272881 A272882 A272883

KEYWORD

nonn

AUTHOR

Vladimir Shevelev, May 08 2016

EXTENSIONS

More terms from Peter J. C. Moses, May 08 2016

STATUS

approved

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Last modified October 19 01:25 EDT 2019. Contains 328211 sequences. (Running on oeis4.)