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A096357 Lcm[{ad(n)}], i.e. the least common multiple of the anti-divisors of n. 2
2, 3, 6, 4, 30, 15, 6, 84, 42, 40, 90, 36, 30, 33, 2310, 420, 78, 312, 42, 180, 90, 112, 3570, 204, 990, 25080, 114, 60, 126, 4095, 4290, 276, 4830, 24, 150, 23100, 6006, 432, 54, 7140, 14790, 696, 8190, 33852, 17670, 3040, 1386, 1980, 102, 840, 210, 36, 12210 (list; graph; refs; listen; history; text; internal format)
OFFSET

3,1

COMMENTS

See A066272 for definition of anti-divisor. Offset is 3 because 1 and 2 have no anti-divisors.

LINKS

Paolo P. Lava, Table of n, a(n) for n = 3..10000

EXAMPLE

The anti-divisors of 7 are 2,3 and 5, so a(7)=30.

The anti-divisors of 9 are 2 and 6, so a(9)=6.

MAPLE

A096357:=proc(q)

local a, b, k, n;

for n from 3 to q do

a:={}; for k from 2 to n-1 do if abs((n mod k)-k/2)<1 then a:=a union {k}; fi; od; print(lcm(op(a))); od; end:

A096357(1000); # Paolo P. Lava, Feb 19 2013

MATHEMATICA

a096357[n_] := Module[{ad},

ad := Cases[Range[2, n - 1], _?(Abs[Mod[n, #] - #/2] < 1 &)];

If[Length[ad] == 0, 0, LCM @@ ad]] (* Michael De Vlieger, Aug 09 2014*)

PROG

(Python)

from sympy import lcm

A096357 = [lcm([d for d in xrange(2, n, 2) if n%d and not 2*n%d]+[d for d in xrange(3, n, 2) if n%d and 2*n%d in [d-1, 1]]) for n in xrange(3, 10**5)] # Chai Wah Wu, Aug 09 2014

CROSSREFS

Cf. A066272.

Sequence in context: A137524 A282507 A156055 * A091507 A098282 A034855

Adjacent sequences:  A096354 A096355 A096356 * A096358 A096359 A096360

KEYWORD

nonn

AUTHOR

Jon Perry, Jun 30 2004

EXTENSIONS

Offset changed by N. J. A. Sloane, Aug 22 2014

STATUS

approved

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Last modified November 16 12:40 EST 2018. Contains 317272 sequences. (Running on oeis4.)