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 A138857 Numbers such that all subsets of {a(1)^2,...,a(n)^2} have a different sum. 3
 1, 2, 3, 4, 6, 9, 12, 18, 25, 34, 49, 70, 99, 140, 198, 280, 396, 560, 792, 1120, 1584, 2241, 3169, 4482, 6339, 8965, 12678, 17930, 25357, 35860 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Since the ratio of two successive members of A138858 tends to 1:2, we have here lim a(n+1)/a(n) = sqrt(2). More precisely, one has a(n) ~ 2^(n/2+const.). See A138858 for more comments. LINKS FORMULA A138857(n)=sqrt(A138858(n)) PROG (PARI) {s=1; p=0; for( n=1, 23, until( !bitand( s, s>>(p^2) ), p++); s+=s<<(p^2); print1( p, ", "))} CROSSREFS Cf. A138858(n)=a(n)^2, A138856, A138000, A138001, A064934. Sequence in context: A018591 A309591 A018669 * A018130 A160993 A171826 Adjacent sequences:  A138854 A138855 A138856 * A138858 A138859 A138860 KEYWORD nonn AUTHOR M. F. Hasler, Apr 09 2008 EXTENSIONS a(24)-a(30) from Donovan Johnson, Oct 03 2009 STATUS approved

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Last modified January 19 14:53 EST 2020. Contains 331049 sequences. (Running on oeis4.)