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A140959 Number of distinct-digit primes in base n. 0
0, 1, 6, 6, 31, 130, 632, 4418, 34401, 283086, 2586883, 28637741 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Table of n, a(n) for n=1..12.

EXAMPLE

a(1) = 0; a(2) = 1 since only the prime 2 in base 2 has distinct integers, 10_2;

a(3) = 6 since the primes {2, 3, 5, 7, 11 & 19} in base 3 have distinct integers, {2_3, 10_3, 12_3, 21_3, 102_3, 201_3}; etc.

a(10) = 283086 because it is the partial sum of A073532.

MATHEMATICA

f[b_] := Block[{c = 0, k = 1, lmt = b^b}, While[p = Prime@ k; p < lmt, k++; If[ Union[ Length /@ Split@ Sort@ IntegerDigits[p, b]] == {1}, c++ ]]; c]; Array[f, 6]

PROG

(Sage)

def a(n):

    return sum(len(p.digits(n)) == len(set(p.digits(n))) for p in prime_range(n^n)) # Eric M. Schmidt, Oct 26 2014

CROSSREFS

Cf. A073532.

Sequence in context: A279865 A321528 A074002 * A015699 A244416 A165827

Adjacent sequences:  A140956 A140957 A140958 * A140960 A140961 A140962

KEYWORD

nonn,base,hard,more

AUTHOR

Robert G. Wilson v, Jul 25 2008

EXTENSIONS

a(11)-a(12) from Eric M. Schmidt, Oct 29 2014

STATUS

approved

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Last modified April 13 15:23 EDT 2021. Contains 342936 sequences. (Running on oeis4.)