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 A178551 Primes with exactly two 2's. 5
 223, 227, 229, 1223, 1229, 2027, 2029, 2129, 2203, 2207, 2213, 2237, 2239, 2243, 2251, 2267, 2269, 2273, 2281, 2287, 2293, 2297, 2423, 2521, 2621, 2729, 2927, 3221, 3229, 4229, 5227, 6221, 6229, 7229, 8221, 9221, 9227, 10223, 12203, 12211, 12239 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Daniel Starodubtsev, Table of n, a(n) for n = 1..10000 PROG (Python) from sympy import isprime print([i for i in range(10000) if str(i).count('2') == 2 and isprime(i)]) # Daniel Starodubtsev, Mar 29 2020 CROSSREFS Cf. A038618, A178550, A178552, A178553, A178554, A178555, A178556, A178557, A178558. Sequence in context: A234623 A252956 A163653 * A105982 A243766 A153424 Adjacent sequences:  A178548 A178549 A178550 * A178552 A178553 A178554 KEYWORD nonn,base AUTHOR Lekraj Beedassy, May 29 2010 STATUS approved

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Last modified January 25 17:10 EST 2022. Contains 350572 sequences. (Running on oeis4.)