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 A237600 Right-truncatable primes in base 16. 12
 2, 3, 5, 7, 11, 13, 37, 41, 43, 47, 53, 59, 61, 83, 89, 113, 127, 179, 181, 191, 211, 223, 593, 599, 601, 607, 659, 661, 691, 701, 757, 761, 853, 857, 859, 863, 947, 953, 977, 983, 991, 1427, 1429, 1433, 1439, 1811, 1823, 2039, 2879, 2897, 2903, 2909, 3061 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Numbers with these properties: (i) a(n) is a prime and (ii) its image under the endomorphism E(k)-> k\16 = floor(k/16) has the same properties. The sequence has 414 nonzero members. LINKS Stanislav Sykora, Table of n, a(n) for n = 1..414 Stanislav Sykora, PARI/GP scripts for genetic threads EXAMPLE a(414) = 16778492037124607, in hexadecimal notation 3B9BF319BD51FF, belongs to a(n) because each of its hexadecimal prefixes (including itself) is a prime. Being the largest of such numbers, it is also a member of A023107. MATHEMATICA Select[Range@ 3600, AllTrue[Most[DeleteDuplicates@ FixedPointList[f, #]], PrimeQ] &] (* Michael De Vlieger, Mar 07 2015, Version 10 *) PROG (PARI) GT_Trunc1(nmax, prop, b=10) = { \\ See the link for details   my (n=0, v=vector(nmax), g=1, lgs=1, lge, an, c);   for (k=1, b-1, if (prop(k), v[n++]=k));   lge=n; c=lge-lgs+1;   while (c, g++; for (k=lgs, lge, for (m=0, b-1, an=b*v[k]+m;     if (prop(an), v[n++]=an; if (n>=nmax, return (v))); ); );     lgs=lge+1; lge=n; c=lge-lgs+1; );   if (n, return (v[1..n]));   print("No solution"); } v = GT_Trunc1(1000000, isprime, 16) (PARI) isok(n) = { while(n, if(!isprime(n), return(0)); n\=16); 1; } for(n=2, 10^9, if(isok(n), print1(n, ", "))); \\ Joerg Arndt, Mar 07 2015 (Python) from gmpy2 import is_prime A237600_list = [] for n in range(1, 10**9): ....if is_prime(n): ........s = format(n, 'x') ........for i in range(1, len(s)): ............if not is_prime(int(s[:-i], 16)): ................break ........else: ............A237600_list.append(n) # Chai Wah Wu, Apr 16 2015 CROSSREFS Cf. A023107, A024770 (base 10), A237601, A237602, A254756. Sequence in context: A187614 A191077 A262377 * A228199 A128292 A140464 Adjacent sequences:  A237597 A237598 A237599 * A237601 A237602 A237603 KEYWORD nonn,base,fini,full AUTHOR Stanislav Sykora, Feb 15 2014 STATUS approved

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Last modified August 14 15:50 EDT 2018. Contains 313751 sequences. (Running on oeis4.)