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 A045708 Primes with first digit 2. 24
 2, 23, 29, 211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271, 277, 281, 283, 293, 2003, 2011, 2017, 2027, 2029, 2039, 2053, 2063, 2069, 2081, 2083, 2087, 2089, 2099, 2111, 2113, 2129, 2131, 2137, 2141, 2143, 2153, 2161, 2179, 2203, 2207, 2213, 2221 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Reinhard Zumkeller, Table of n, a(n) for n = 1..10000 FORMULA See A045707 for comments on density of these sequences. MATHEMATICA Select[Table[Prime[n], {n, 3000}], First[IntegerDigits[#]]==2 &] (* Vincenzo Librandi, Aug 08 2014 *) PROG (Haskell) a045708 n = a045708_list !! (n-1) a045708_list = filter ((== 2) . a000030) a000040_list -- Reinhard Zumkeller, Mar 16 2012 (Magma) [p: p in PrimesUpTo(2300) | Intseq(p)[#Intseq(p)] eq 2]; // Vincenzo Librandi, Aug 08 2014 (Python) from sympy import isprime def agen(limit=float('inf')): yield 2 digits, adder = 1, 20 while True: for i in range(1, 10**digits, 2): test = adder + i if test > limit: return if isprime(test): yield test digits, adder = digits+1, adder*10 agento = lambda lim: agen(limit=lim) print(list(agento(2222))) # Michael S. Branicky, Feb 23 2021 CROSSREFS Cf. A000040. For primes with initial digit d (1 <= d <= 9) see A045707, A045708, A045709, A045710, A045711, A045712, A045713, A045714, A045715; A073517, A073516, A073515, A073514, A073513, A073512, A073511, A073510, A073509 Cf. A000030, subsequence of A208272. Column k=2 of A262369. Sequence in context: A062653 A208272 A306086 * A090150 A106102 A053232 Adjacent sequences: A045705 A045706 A045707 * A045709 A045710 A045711 KEYWORD nonn,base,easy AUTHOR Felice Russo EXTENSIONS More terms from Erich Friedman. Offset fixed by Reinhard Zumkeller, Mar 15 2012 STATUS approved

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Last modified December 8 14:49 EST 2023. Contains 367680 sequences. (Running on oeis4.)