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 A282455 Repdigit numbers that are the sum of two nonzero squares. 0
 2, 5, 8, 333, 666 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS This sequence is complete - there are no other terms. LINKS Table of n, a(n) for n=1..5. Wikipedia, Sum of two squares theorem Index entries for sequences related to sums of squares FORMULA A000404 INTERSECT A010785. EXAMPLE 666 = 15^2 + 21^2, therefore 666 is a term. PROG (Magma) lst:=[]; for e in [1..3] do a:=Truncate((10^e-1)/9); for x in [1..9] do n:=a*x; f:=Factorization(n); if IsSquare(n) and not IsZero([x: x in [1..#f] | f[x][1] mod 4 eq 1]) or not IsSquare(n) and IsZero([x: x in [1..#f] | IsOdd(f[x][2]) and f[x][1] mod 4 eq 3]) then Append(~lst, n); end if; end for; end for; lst; CROSSREFS Cf. A010785. Sequence in context: A162709 A242875 A222897 * A323457 A011039 A346045 Adjacent sequences: A282452 A282453 A282454 * A282456 A282457 A282458 KEYWORD nonn,base,fini,full AUTHOR Arkadiusz Wesolowski, Feb 15 2017 STATUS approved

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Last modified September 13 04:25 EDT 2024. Contains 375859 sequences. (Running on oeis4.)