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A105238 Primes concatenated from four consecutive odd numbers. 1
23252729, 77798183, 115117119121, 197199201203, 211213215217, 221223225227, 227229231233, 265267269271, 281283285287, 311313315317, 317319321323, 343345347349, 373375377379, 397399401403, 403405407409, 433435437439 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

FORMULA

For positive n: {Concatenate((2n+1), (2n+3), (2n+5), (2n+7))} Intersect {Primes A000040}.

MATHEMATICA

Select[FromDigits/@(Flatten[IntegerDigits[#]]&/@Partition[Range[ 1, 501, 2], 4, 1]), PrimeQ] (* Harvey P. Dale, Jul 18 2013 *)

CROSSREFS

Cf. A000040, A032625.

Sequence in context: A157079 A321065 A183736 * A252396 A236366 A097617

Adjacent sequences: A105235 A105236 A105237 * A105239 A105240 A105241

KEYWORD

base,easy,nonn

AUTHOR

Jonathan Vos Post, Apr 12 2005

STATUS

approved

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Last modified February 3 17:00 EST 2023. Contains 360044 sequences. (Running on oeis4.)