New sequence??
Richard Guy
rkg at cpsc.ucalgary.ca
Thu Apr 1 20:34:54 CEST 2004
The following quote from UPINT
\usection{B30}{A small set whose product is square.}
Erd\H{o}s, Graham \& Selfridge want us to find the least value of $t_n$
so that the integers $n+1$, $n+2$, \ldots, $n+t_n$ contain a subset
the product of whose members with $n$ is a square.
The \Gidx{Thue--Siegel theorem} implies that
$t_n\rightarrow\infty$ with $n$, faster than a power of $\ln n$.
suggests that t_n should appear in OEIS. P'raps it does,
but you all know that I'm not a good looker.
Not surprisingly it starts off like A080883,
but a(26) = 9, I believe, because
27 * 28 * 30 * 32 * 35 = 2520^2
1, 3, 2, 1, 5, 4, 3, 2, 1, 7, 6, 5, 4, 3, 2, 1,
9, 8, 7, 6, 5, 4, 3, 2, 1, 10, 9, 9, 8, 7, 6, 5,
4, 3, 2, 1, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3,
2, 1, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4,
3, 2, 1, 16, 15, 15, 14, 13, 12, 11, 10, 9, 8,
7, 6, 5, 4, 3, 2, 1,
... probably lots of errors. The values of
a(64) and a(65) are based on
66 * 70 * 75 * 77 * 80 = 46200^2
R.
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