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 A110975 Numbers n such that 2*prime(n) - prime(n+1) is a square. 2
 1, 2, 5, 6, 11, 24, 49, 50, 73, 87, 182, 183, 202, 203, 307, 309, 379, 458, 459, 520, 677, 961, 1001, 1475, 1618, 1619, 1769, 2089, 2427, 2428, 3303, 3378, 4090, 4397, 4944, 5444, 5969, 6496, 6497, 7653, 8557, 8871, 8873, 9091, 9526, 10524, 11580, 11824 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Robert Israel, Table of n, a(n) for n = 1..1000 MAPLE Res:= NULL: p:= 2; count:= 0: for n from 1 while count < 100 do q:= p; p:= nextprime(p); if issqr(2*q-p) then count:= count+1; Res:= Res, n; fi od: Res; # Robert Israel, Mar 02 2020 MATHEMATICA Select[Range[12000], IntegerQ[(2Prime[ # ] - Prime[ # + 1])^(1/2)] &] (* Ray Chandler, Oct 07 2005 *) Position[2#[[1]]-#[[2]]&/@Partition[Prime[Range[12000]], 2, 1], _?(IntegerQ[ Sqrt[#]]&)]//Flatten (* Harvey P. Dale, Apr 30 2019 *) CROSSREFS Cf. A110970. Sequence in context: A255310 A051217 A275522 * A190120 A069789 A332683 Adjacent sequences: A110972 A110973 A110974 * A110976 A110977 A110978 KEYWORD nonn AUTHOR Giovanni Teofilatto, Sep 28 2005 EXTENSIONS Corrected and extended by Ray Chandler, Oct 07 2005 STATUS approved

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Last modified February 24 05:49 EST 2024. Contains 370293 sequences. (Running on oeis4.)