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A035479 (-1)sigma sequence: a(n)=(-1)sigma(a(n-1)), 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))). 0
624, 696, 728, 936, 1716, 1200, 1682, 869, 780, 480, 488, 780, 480, 488, 780, 480, 488, 780, 480, 488 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

This sequence becomes a cycle of period 3: 780, 480, 488. It is called (-1)sigma sociable of order 3.

LINKS

Table of n, a(n) for n=0..19.

EXAMPLE

Factorizations: 2^4*3*13,2^3*3*29,2^3*7*13,2^3*3^2*13,2^2*3*11*13, 2^4*3*5^2,2*29^2,11*79,2^2*3*5*13,2^5*3*5,2^3*61

CROSSREFS

Sequence in context: A158373 A265119 A283898 * A180453 A216843 A043368

Adjacent sequences:  A035476 A035477 A035478 * A035480 A035481 A035482

KEYWORD

nonn

AUTHOR

Yasutoshi Kohmoto

STATUS

approved

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Last modified January 22 05:11 EST 2019. Contains 319353 sequences. (Running on oeis4.)