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A076586 Total number of right truncatable primes in base n. 15
0, 4, 7, 14, 36, 19, 68, 68, 83, 89, 179, 176, 439, 373, 414, 473, 839, 1010, 1577, 2271, 2848, 1762, 3376, 5913, 6795, 6352, 10319, 5866, 14639, 13303, 19439, 29982, 38956, 39323, 58857, 41646, 68371, 80754, 128859, 81453, 175734, 161438, 228543, 396274, 538797 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,2

LINKS

Seth A. Troisi, Table of n, a(n) for n = 2..100 (terms n=2..53 from Martin Renner)

I. O. Angell and H. J. Godwin, On Truncatable Primes, Math. Comput. 31, 265-267, 1977.

Index entries for sequences related to truncatable primes

PROG

(Python)

from sympy import isprime, primerange

from sympy.ntheory.digits import digits

def fromdigits(digs, base):

    return sum(d*base**i for i, d in enumerate(digs))

def a(n):

    prime_lists, an = [(p, ) for p in primerange(1, n)], 0

    digits = 1

    while len(prime_lists) > 0:

        an += len(prime_lists)

        candidates = set((d, )+p for p in prime_lists for d in range(1, n))

        prime_lists = [c for c in candidates if isprime(fromdigits(c, n))]

        digits += 1

    return an

print([a(n) for n in range(2, 27)]) # Michael S. Branicky, May 03 2022

CROSSREFS

Cf. A024763, A024764, A024765, A024766, A024767, A024768, A024769, A024770, A076623.

Sequence in context: A199628 A049945 A234576 * A240266 A064961 A137053

Adjacent sequences:  A076583 A076584 A076585 * A076587 A076588 A076589

KEYWORD

nonn,base

AUTHOR

Martin Renner, Oct 20 2002, Sep 24 2007

STATUS

approved

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Last modified July 5 23:40 EDT 2022. Contains 355108 sequences. (Running on oeis4.)