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A350803
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Numbers k with at least one partition into two parts (s,t), s<=t such that t | s*k.
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3
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2, 4, 6, 8, 10, 12, 14, 15, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 35, 36, 38, 40, 42, 44, 45, 46, 48, 50, 52, 54, 56, 58, 60, 62, 63, 64, 66, 68, 70, 72, 74, 75, 76, 77, 78, 80, 82, 84, 86, 88, 90, 91, 92, 94, 96, 98, 99, 100, 102, 104, 105, 106, 108, 110, 112, 114, 116
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OFFSET
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1,1
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COMMENTS
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A299174 is a subsequence because, if k = 2*u, we have s=t=u, s<=t, and u | u*k.
A082663 is another subsequence because, if k = p*q with p < q < 2p, then with s = k-p^2 = p*(q-p) and t = p^2, we have s <= t and p^2 | p*(q-p) * (pq).
It seems that A090196 is the subsequence of odd terms. (End)
gcd(s, t) > 1 where s and t and k > 2 are as in name. - David A. Corneth, Jan 22 2022
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LINKS
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EXAMPLE
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15 is in the sequence since 15 = 6+9 where 9 | 6*15 = 90.
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PROG
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(PARI) f(n) = sum(s=1, n\2, !((s*n)%(n-s))); \\ A338021
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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