

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




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^(4p1)*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, #A1, 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



