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 A178919 Smallest of three consecutive integers divisible respectively by three consecutive squares greater than 1. 2
 2223, 5823, 9423, 13023, 16623, 20223, 23823, 27423, 31023, 32975, 34623, 38223, 41823, 45423, 49023, 52623, 56223, 59823, 63423, 67023, 70623, 74223, 77075, 77823, 81423, 85023, 88623, 92223, 95823, 99423, 103023, 106623, 110223 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Amiram Eldar, Table of n, a(n) for n = 1..10000 EXAMPLE 5823 is a term as 5823, 5824 and 5825 are divisible by 9, 16 and 25 respectively. MAPLE with(numtheory):for n from 1 to 200000 do: k:=0:q:=floor(sqrt(n)):for m from   2 to q do: p1:=m^2:p2:=(m+1)^2:p3:=(m+2)^2:if irem(n, p1)=0 and irem(n+1, p2)=0   and irem(n+2, p3)=0 and k=0 then k:=1:printf(`%d, `, n):else fi:od:od: MATHEMATICA f[p_, e_] := p^Floor[e/2]; maxsq[n_] := Times@@ (f @@@ FactorInteger[n]); aQ[n_] := (s = maxsq[n]) > 1 && AnyTrue[Rest @ Divisors[s], Divisible[n+1, (#+1)^2] && Divisible[n+2, (#+2)^2] &]; Select[Range[50000], aQ] (* Amiram Eldar, Sep 09 2019 *) PROG (Sage) is_A178919 = lambda n: any(all(((k+x)**2).divides(n+x) for x in range(3)) for k in divisors(n) if k > 1) # D. S. McNeil, Dec 29 2010 CROSSREFS Cf. A178918. Sequence in context: A043500 A118116 A053395 * A205225 A236496 A208181 Adjacent sequences:  A178916 A178917 A178918 * A178920 A178921 A178922 KEYWORD nonn AUTHOR Michel Lagneau, Dec 29 2010 STATUS approved

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Last modified September 17 19:06 EDT 2021. Contains 347489 sequences. (Running on oeis4.)