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A049058 Second element s of (-1)sigma sociable triple (r,s,t): s=(-1)sigma(r), t=(-1)sigma(s), r=(-1)sigma(t), where if x=Product p(i)^r(i), then (-1)sigma(x)=Product(-1+(Sum p(i)^s(i), s(i)=1 to r(i))). 5
60, 120, 480, 1464, 7680, 24504, 490080 (list; graph; refs; listen; history; internal format)
OFFSET

0,1

EXAMPLE

Factorizations 2^2*3*5, 2^3*3*5, 2^5*3*5, 2^3*3*61, 2^9*3*5, 2^3*3*1021, 2^5*3*5*1021

CROSSREFS

Cf. A049057, A049059, A049060.

Sequence in context: A169823 A087004 A177871 * A056501 A056491 A044247

Adjacent sequences:  A049055 A049056 A049057 * A049059 A049060 A049061

KEYWORD

nonn

AUTHOR

Yasutoshi Kohmoto (zbi74583(AT)boat.zero.ad.jp)

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Last modified February 14 20:13 EST 2012. Contains 205663 sequences.