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 A154673 Averages of twin prime pairs n such that n*7 and n/7 are squares. 4
 2268, 6300, 30492, 49392, 81648, 100800, 170352, 183708, 197568, 211932, 242172, 363888, 444528, 681408, 847728, 1032192, 1342908, 1694448, 1820700, 2041200, 3049200 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS MATHEMATICA lst={}; Do[If[PrimeQ[n-1]&&PrimeQ[n+1], s=(n*7)^(1/2); If[Floor[s]==s, AppendTo[lst, n]]], {n, 6, 10!, 6}]; lst...and/or... lst={}; Do[If[PrimeQ[n-1]&&PrimeQ[n+1], s=(n/7)^(1/2); If[Floor[s]==s, AppendTo[lst, n]]], {n, 6, 10!, 6}]; lst CROSSREFS Cf. A154670, A154671, A154672 Sequence in context: A272376 A288883 A206212 * A130179 A205756 A205586 Adjacent sequences:  A154670 A154671 A154672 * A154674 A154675 A154676 KEYWORD nonn AUTHOR Vladimir Joseph Stephan Orlovsky, Jan 13 2009 STATUS approved

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