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A318252 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
13312, 81551360, 1946157056, 128580583424, 12695923326976, 33590071001088, 2182874178519040, 59672695062659072 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
The lesser numbers in each pair are in A318251.
Analogous to A002046 as A163272 is analogous to A000396.
If p and 4p+1 are primes then 2^(4p-2)*(4p+1) is in this sequence.
LINKS
EXAMPLE
13312 is in the sequence since A074206(13312) = 6144 and A074206(6144) = 13312.
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
Sequence in context: A345840 A031620 A251339 * A034625 A283155 A254851
KEYWORD
nonn,more
AUTHOR
Amiram Eldar, Aug 22 2018
STATUS
approved

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Last modified June 22 09:08 EDT 2024. Contains 373568 sequences. (Running on oeis4.)