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A078637 rad{n(n+1)(n+2)}, where rad(m) = largest squarefree number dividing m (see A007947). 3
6, 6, 30, 30, 210, 42, 42, 30, 330, 330, 858, 546, 2730, 210, 510, 102, 1938, 570, 3990, 2310, 10626, 1518, 690, 390, 390, 546, 1218, 6090, 26970, 930, 2046, 1122, 39270, 3570, 7770, 4218, 54834, 7410, 15990, 8610, 74046, 19866, 14190, 7590, 32430, 6486 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(n) = A007947(A033931(n)). - Reinhard Zumkeller, Jul 04 2012

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

FORMULA

a(n) = rad(n)*rad(n+1)*rad(n+2) if n odd; or rad(n/2)*rad(n+1)*rad(n/2+1) if n even - C. Ronaldo (aga_new_ac(AT)hotmail.com), Dec 13 2004

EXAMPLE

a(3)=rad(3.4.5)=30

MAPLE

with(numtheory):rad:=proc(n) local s, i: s:=ifactors(n)[2]: RETURN(mul(s[i][1], i=1..nops(s))): end; seq(rad(n*(n+1)*(n+2)), n=1..60); seq(piecewise(n mod 2=0, rad(n/2)*rad(n+1)*rad(n/2+1), rad(n)*rad(n+1)*rad(n+2)), n=1..60); (C. Ronaldo)

PROG

(PARI) rad(n)=local(p, i); p=factor(n)[, 1]; prod(i=1, length(p), p[i])

for (k=1, 100, print1(rad(k*(k+1)*(k+2))", "))

(Haskell)

a078637 n = a007947 $ product [n..n+2] -- Reinhard Zumkeller, Jul 04 2012

CROSSREFS

Cf. A007947.

Sequence in context: A066714 A054436 A055522 * A147799 A071021 A279865

Adjacent sequences:  A078634 A078635 A078636 * A078638 A078639 A078640

KEYWORD

nonn

AUTHOR

Jon Perry, Dec 12 2002

STATUS

approved

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Last modified November 13 01:32 EST 2018. Contains 317118 sequences. (Running on oeis4.)