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A050264 Weak veryprimes. 1
2, 3, 5, 7, 11, 13, 17, 19, 23, 37, 43, 47, 53, 67, 73, 103, 107, 137, 157, 173, 227, 347, 487, 773 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

No other terms less than 10^10 other than those stated above. - Robert G. Wilson v, Feb 10 2018

LINKS

Table of n, a(n) for n=1..24.

Eric Weisstein's World of Mathematics, Veryprime

MATHEMATICA

veryprimeQ[n_] := Block[{p = 2}, While[p^2 <= n && 2 Abs[2 Mod[n, p] -p] <= p, p = NextPrime@ p]; p^2 > n]; Select[ Prime[ Range[140]], veryprimeQ](* Jean-Fran├žois Alcover, Nov 30 2011 and slightly modified by Robert G. Wilson v, Feb 10 2018 *)

PROG

(Haskell)

a050264 n = a050264_list !! (n-1)

a050264_list = filter chi [2..] where

   chi n = f a000040_list where

      f (p:ps) | p*p > n   = True

               | otherwise = 2 * abs (2 * (n `mod` p) - p) <= p && f ps

-- Reinhard Zumkeller, Aug 11 2011

CROSSREFS

Sequence in context: A105581 A258433 A262363 * A075239 A255073 A008792

Adjacent sequences:  A050261 A050262 A050263 * A050265 A050266 A050267

KEYWORD

nonn,nice

AUTHOR

Eric W. Weisstein, Jim Ferry (jferry(AT)uiuc.edu)

STATUS

approved

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Last modified May 23 20:23 EDT 2019. Contains 323528 sequences. (Running on oeis4.)