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Primes not containing the digit '7'.
23

%I #48 Aug 04 2023 18:59:27

%S 2,3,5,11,13,19,23,29,31,41,43,53,59,61,83,89,101,103,109,113,131,139,

%T 149,151,163,181,191,193,199,211,223,229,233,239,241,251,263,269,281,

%U 283,293,311,313,331,349,353,359,383,389,401,409,419,421,431,433,439

%N Primes not containing the digit '7'.

%C Subsequence of primes of A052419. - _Michel Marcus_, Feb 22 2015

%C Maynard proves that this sequence is infinite and in particular contains the expected number of elements up to x, on the order of x^(log 9/log 10)/log x. - _Charles R Greathouse IV_, Apr 08 2016

%H Alois P. Heinz, <a href="/A038615/b038615.txt">Table of n, a(n) for n = 1..20000</a>

%H Marianne Freiberger, <a href="https://plus.maths.org/content/missing-7s">Primes without 7s</a>, +plus magazine, August 2016.

%H M. F. Hasler, <a href="/wiki/Numbers_avoiding_certain_digits">Numbers avoiding certain digits</a>, OEIS wiki, Jan 12 2020.

%H James Maynard, <a href="http://arxiv.org/abs/1604.01041">Primes with restricted digits</a>, arXiv:1604.01041 [math.NT], 2016.

%H James Maynard and Brady Haran, <a href="https://www.youtube.com/watch?v=eeoBCS7IEqs">Primes without a 7</a>, Numberphile video (2019).

%F Intersection of A000040 (primes) and A052419 (numbers with no digit 7). - _M. F. Hasler_, Jan 11 2020

%F a(n) ~ n^(log 10/log 9) log n. - _Charles R Greathouse IV_, Aug 03 2023

%t Select[Prime[Range[70]], DigitCount[#, 10, 7] == 0 &] (* _Vincenzo Librandi_, Aug 08 2011 *)

%o (Magma) [ p: p in PrimesUpTo(500) | not 7 in Intseq(p) ]; // _Bruno Berselli_, Aug 08 2011

%o (PARI) lista(nn)=forprime(p=2, nn, if (!vecsearch(vecsort(digits(p),,8), 7), print1(p, ", "));); \\ _Michel Marcus_, Feb 22 2015

%o (PARI) (A038615_upto(N)=select( is_A052419, primes([1,N])))(444) \\ i.e.: {is_A038615(n)=is_A052419(n)&&isprime(n)}; {is_A052419(n)=!setsearch(Set(digits(n)),7)}. - _M. F. Hasler_, Jan 11 2020

%Y Cf. A000040, A052419.

%Y Primes having no digit d = 0..9 are A038618, A038603, A038604, A038611, A038612, A038613, A038614, this sequence, A038616, and A038617, respectively.

%K nonn,easy,base

%O 1,1

%A Vasiliy Danilov (danilovv(AT)usa.net), Jul 15 1998

%E Offset corrected by _Arkadiusz Wesolowski_, Aug 07 2011