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A076586 Total number of right truncatable primes in base n.

%I A076586 #23 May 03 2022 15:16:46
%S A076586 0,4,7,14,36,19,68,68,83,89,179,176,439,373,414,473,839,1010,1577,
%T A076586 2271,2848,1762,3376,5913,6795,6352,10319,5866,14639,13303,19439,
%U A076586 29982,38956,39323,58857,41646,68371,80754,128859,81453,175734,161438,228543,396274,538797
%N A076586 Total number of right truncatable primes in base n.
%H A076586 Seth A. Troisi, <a href="/A076586/b076586.txt">Table of n, a(n) for n = 2..100</a> (terms n=2..53 from Martin Renner)
%H A076586 I. O. Angell and H. J. Godwin, <a href="http://dx.doi.org/10.1090/S0025-5718-1977-0427213-2">On Truncatable Primes</a>, Math. Comput. 31, 265-267, 1977.
%H A076586 <a href="/index/Tri#tprime">Index entries for sequences related to truncatable primes</a>
%o A076586 (Python)
%o A076586 from sympy import isprime, primerange
%o A076586 from sympy.ntheory.digits import digits
%o A076586 def fromdigits(digs, base):
%o A076586     return sum(d*base**i for i, d in enumerate(digs))
%o A076586 def a(n):
%o A076586     prime_lists, an = [(p,) for p in primerange(1, n)], 0
%o A076586     digits = 1
%o A076586     while len(prime_lists) > 0:
%o A076586         an += len(prime_lists)
%o A076586         candidates = set((d,)+p for p in prime_lists for d in range(1, n))
%o A076586         prime_lists = [c for c in candidates if isprime(fromdigits(c, n))]
%o A076586         digits += 1
%o A076586     return an
%o A076586 print([a(n) for n in range(2, 27)]) # _Michael S. Branicky_, May 03 2022
%Y A076586 Cf. A024763, A024764, A024765, A024766, A024767, A024768, A024769, A024770, A076623.
%K A076586 nonn,base
%O A076586 2,2
%A A076586 _Martin Renner_, Oct 20 2002, Sep 24 2007