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 A069489 Primes > 1000 in which every substring of length 3 is also prime. 55
 1013, 1019, 1031, 1097, 1277, 1373, 1499, 1571, 1733, 1811, 1997, 2113, 2239, 2293, 2719, 3079, 3137, 3313, 3373, 3491, 3499, 3593, 3673, 3677, 3733, 3739, 3797, 4013, 4019, 4211, 4337, 4397, 4673, 4877, 4919, 5233, 5419, 5479, 6011, 6073, 6079, 6131 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Minimum number of digits is taken to be 4 as all 3-digit primes would be trivial members. Zero may occur only as second digit from left. - Zak Seidov, Dec 28 2020 All the digits after the two first digits from left are necessarily odd. - Bernard Schott, Mar 20 2022 LINKS Reinhard Zumkeller, Table of n, a(n) for n = 1..1000 EXAMPLE 11317 is a term as the three substrings of length 3 i.e. 113,131 and 317 all are primes. MATHEMATICA Do[ If[ Union[ PrimeQ[ Map[ FromDigits, Partition[ IntegerDigits[ Prime[n]], 3, 1]]]] == {True}, Print[ Prime[n]]], {n, PrimePi[1000] + 1, 10^3}] Select[Prime[Range[169, 800]], AllTrue[FromDigits/@Partition[ IntegerDigits[ #], 3, 1], PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Mar 05 2019 *) PROG (Haskell) a069489 n = a069489_list !! (n-1) a069489_list = filter g \$ dropWhile (<= 1000) a000040_list where g x = x < 100 || a010051 (x `mod` 1000) == 1 && g (x `div` 10) -- Reinhard Zumkeller, Apr 07 2014 CROSSREFS Cf. A069488 and A069490. Cf. A211685, A010051, A000040. Sequence in context: A166975 A266369 A165295 * A157008 A161404 A252634 Adjacent sequences: A069486 A069487 A069488 * A069490 A069491 A069492 KEYWORD nonn,base AUTHOR Amarnath Murthy, Mar 30 2002 EXTENSIONS Edited, corrected and extended by Robert G. Wilson v, Apr 12 2002 STATUS approved

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Last modified April 25 10:34 EDT 2024. Contains 371967 sequences. (Running on oeis4.)