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A135974 a(n) = the smallest integer m > n such that d(m) > d(n), where d(n) = number of divisors of n. 0
2, 4, 4, 6, 6, 12, 8, 12, 10, 12, 12, 24, 14, 16, 16, 18, 18, 24, 20, 24, 24, 24, 24, 36, 26, 28, 28, 30, 30, 36, 32, 36, 36, 36, 36, 48, 38, 40, 40, 48, 42, 48, 44, 48, 48, 48, 48, 60, 50, 54, 52, 54, 54, 60, 56, 60, 60, 60, 60, 120, 62, 63, 64, 66, 66, 72, 68, 70, 70 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..69.

EXAMPLE

a(6)=12 because 6 has 4 divisors and the smallest integer > 6 which has more than 4 divisors is 12.

MAPLE

with(numtheory): a:=proc (n) local m: for m from n+1 while tau(m) <= tau(n) do end do: m end proc: seq(a(n), n=1..60); # Emeric Deutsch, Mar 21 2008

MATHEMATICA

a = {}; For[n = 1, n < 70, n++, i = n + 1; While[ ! DivisorSigma[0, i] > DivisorSigma[0, n], i++ ]; AppendTo[a, i]]; a (* Stefan Steinerberger, Mar 16 2008 *)

CROSSREFS

Cf. A000005, A112275.

Sequence in context: A226951 A251557 A231901 * A153494 A205404 A322372

Adjacent sequences:  A135971 A135972 A135973 * A135975 A135976 A135977

KEYWORD

nonn

AUTHOR

Leroy Quet, Mar 02 2008

EXTENSIONS

More terms from Stefan Steinerberger, Mar 16 2008

STATUS

approved

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Last modified June 20 17:51 EDT 2019. Contains 324234 sequences. (Running on oeis4.)