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A318251 Lesser of amicable numbers pair (m, n) such that n = H(m) and m = H(n) where H(n) = A074206(n) is the number of ordered factorizations of n. 1
6144, 19329024, 939524096, 4026531840, 309237645312, 6146186280960, 52158082842624, 29273397577908224 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The larger numbers in each pair are in A318252.

Analogous to A002025 as A163272 is analogous to A000396.

If p and 4p+1 are primes then 2^(4p-1)*p is in this sequence, therefore if A023212 is infinite then also this sequence is.

The terms were calculated using an extended list of terms of A025487.

LINKS

Table of n, a(n) for n=1..8.

EXAMPLE

6144 is in the sequence since A074206(6144) = 13312 and A074206(13312) = 6144.

PROG

(PARI) f(n) = if( n<2, n>0, my(A = divisors(n)); sum(k=1, #A-1, f(A[k])));

isok(n)={my(a=f(n)); a>n && f(a)==n; } \\ Michel Marcus, Sep 26 2018

CROSSREFS

Cf. A023212, A074206, A090866, A163272, A318252.

Sequence in context: A251787 A203982 A204626 * A281265 A007992 A033288

Adjacent sequences:  A318248 A318249 A318250 * A318252 A318253 A318254

KEYWORD

nonn,more

AUTHOR

Amiram Eldar, Aug 22 2018

STATUS

approved

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Last modified December 9 03:23 EST 2021. Contains 349625 sequences. (Running on oeis4.)