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Larger 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

%I #7 Sep 27 2018 05:04:32

%S 13312,81551360,1946157056,128580583424,12695923326976,33590071001088,

%T 2182874178519040,59672695062659072

%N Larger 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.

%C The lesser numbers in each pair are in A318251.

%C Analogous to A002046 as A163272 is analogous to A000396.

%C If p and 4p+1 are primes then 2^(4p-2)*(4p+1) is in this sequence.

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

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

%o isok(n)={my(a=f(n)); a<n && f(a)==n;} \\ _Michel Marcus_, Sep 26 2018

%Y Cf. A023212, A074206, A090866, A163272, A318251.

%K nonn,more

%O 1,1

%A _Amiram Eldar_, Aug 22 2018