OFFSET
1,1
LINKS
Reinhard Zumkeller, Table of n, a(n) for n = 1..250
Eric Weisstein's World of Mathematics, Twin Primes.
FORMULA
EXAMPLE
MATHEMATICA
tdpfQ[n_]:=Module[{fi=FactorInteger[n][[;; , 1]]}, Length[fi]==2&&fi[[2]]-fi[[1]]==2]; Select[Range[20000], tdpfQ] (* Harvey P. Dale, Mar 04 2023 *)
PROG
(Haskell)
a143202 n = a143202_list !! (n-1)
a143202_list = filter (\x -> a006530 x - a020639 x == 2) [1, 3..]
-- Reinhard Zumkeller, Sep 13 2011
CROSSREFS
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Aug 12 2008
STATUS
approved