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A046709 Irrational unitary phi amicable number: two numbers which satisfy uphi(a)=uphi(b)=2*(a^2-b^2)^(1/2) where if x=Product p(i)^r(i) then uphi(x)=Product (p(i)^r(i)-1) (A047994). 1
25200, 982800, 1562400, 60933600, 6854400, 267321600, 798939187200, 31158628300800, 450964684800, 17587622707200, 118216784402841600, 459775632811622400, 1936908127288531353600, 75539416964252722790400 (list; graph; refs; listen; history; text; internal format)
OFFSET

4,1

COMMENTS

Factorizations: 2^4*3^2*5^2*7, 2^4*3^3*13*5^2*7, 2^5*3^2*31*5^2*7, 2^5*3^3*13*31*5^2*7, ...

LINKS

Table of n, a(n) for n=4..17.

CROSSREFS

Cf. A046710.

Sequence in context: A296097 A076583 A226501 * A179723 A174825 A269041

Adjacent sequences:  A046706 A046707 A046708 * A046710 A046711 A046712

KEYWORD

nonn

AUTHOR

Yasutoshi Kohmoto

STATUS

approved

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Last modified July 10 00:00 EDT 2020. Contains 335570 sequences. (Running on oeis4.)