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 A290098 Characteristic function for A003658 (fundamental discriminants of real quadratic fields). 3
 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 1 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1 LINKS Antti Karttunen, Table of n, a(n) for n = 1..65537 MATHEMATICA Block[{nn = 105, t}, t = ConstantArray[0, nn]; ReplacePart[t, Map[# -> 1 &, Select[Range@ nn, NumberFieldDiscriminant@ Sqrt@ # == # &]]]] (* Michael De Vlieger, Aug 23 2017 *) PROG (PARI) A290098(n) = isfundamental(n); CROSSREFS Cf. A003658, A086669. Sequence in context: A121262 A181923 A339825 * A102243 A173859 A202108 Adjacent sequences:  A290095 A290096 A290097 * A290099 A290100 A290101 KEYWORD nonn AUTHOR Antti Karttunen, Aug 22 2017 STATUS approved

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Last modified July 29 01:22 EDT 2021. Contains 346340 sequences. (Running on oeis4.)