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A060239 det(P*Q)/n! where P, Q are n X n matrices with P[i,j]=lcm(i,j), Q[i,j]=gcd(i,j). 3
1, -1, 4, -8, 128, 512, -18432, 73728, -884736, -14155776, 1415577600, 11324620800, -1630745395200, -58706834227200, -3757237390540800, 30057899124326400, -7694822175827558400, -92337866109930700800 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Enrique PĂ©rez Herrero, Table of n, a(n) for n = 1..100

FORMULA

a(n)=A001088(n)*A060238(n)/n!

PROG

(Sage)

def A060239(n):

....P = Matrix(lambda i, j: lcm(i+1, j+1), nrows=n)

....Q = Matrix(lambda i, j: gcd(i+1, j+1), nrows=n)

....return (P*Q).det()/factorial(n) # [D. S. McNeil, Jan 16 2011]

CROSSREFS

Cf. A001088, A060238.

Sequence in context: A182967 A013049 A193155 * A127943 A012498 A180745

Adjacent sequences:  A060236 A060237 A060238 * A060240 A060241 A060242

KEYWORD

sign

AUTHOR

MCKAY john (mckay(AT)cs.concordia.ca), Mar 21 2001

STATUS

approved

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Last modified November 18 01:16 EST 2018. Contains 317279 sequences. (Running on oeis4.)