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 A086204 Decimal equivalents of strings in A086884. 1
 2, 2, 47, 151, 4001, 4001, 100207, 41532851, 447045215857, 282607273285049, 5678228814363947 (list; graph; refs; listen; history; text; internal format)
 OFFSET 2,1 LINKS Table of n, a(n) for n=2..12. Mersenneforum.org, Multibase primes EXAMPLE a(5) = 10010111 because 10010111 (base 2) = 151, 10010111 (base 3) = 2281, 10010111 (base 4) = 16661 and 10010111 (base 5) = 78781 are all prime and 10010111 is the smallest such string. MATHEMATICA a[n_] := (While[b = FromDigits[ IntegerDigits[k, 2]]; Union[ PrimeQ[ Table[ FromDigits[ IntegerDigits[b], i], {i, 2, n}]]] != {True}, k++ ]; b); k = 1; Do[ Print[ a[n]], {n, 2, 10}] PROG (Python) from sympy import isprime def conv(s, b): return sum(b**k for k, bk in enumerate(s[::-1]) if bk=='1') def ok(s, n): return all(isprime(conv(s, b)) for b in range(2, n+1)) def a(n): if n < 4: return 2 k = 3 while not ok(bin(k)[2:], n): k += 2 return int(bin(k)[2:], 2) print([a(n) for n in range(2, 9)]) # Michael S. Branicky, Oct 10 2021 CROSSREFS Cf. A086884. Sequence in context: A303538 A222661 A015167 * A318085 A345267 A316090 Adjacent sequences: A086201 A086202 A086203 * A086205 A086206 A086207 KEYWORD nonn,base,more AUTHOR Richard FitzHugh (fitzhughrichard(AT)hotmail.com), Aug 22 2003 EXTENSIONS Edited by Robert G. Wilson v, Aug 24 2003 Two more terms added by James G. Merickel, Feb 15 2010 One more term added by Andreas Höglund, Oct 17 2022 (found by Jim Viebke) STATUS approved

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Last modified December 6 22:36 EST 2023. Contains 367616 sequences. (Running on oeis4.)