

A240886


Primes p equal to the sum in base3 of the digits of all primes < p.


6



23, 31, 47, 59, 695689, 698471, 883517, 992609, 992737, 993037, 1314239, 1324361, 1324571, 1326511, 1327289, 1766291, 3174029
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OFFSET

1,1


COMMENTS

Conjecture: this sequence is finite and all terms are shown.  Robert G. Wilson v, Jul 27 2014
The sum of the digits in base three of all primes < 10^10 is 9694409092.  Robert G. Wilson v, Jul 27 2014


LINKS

Table of n, a(n) for n=1..17.


FORMULA

prime(n) such that, using base 3, prime(n) = sum_{1..n1} A239619(i).


EXAMPLE

For example, 23 = digitsum(primes < 23, base=3) = sum(2) + sum(1,0) + sum(1,2) + sum(2,1) + sum(1,0,2) + sum(1,1,1) + sum(1,2,2) + sum(2,0,1).


MATHEMATICA

p = 2; s = 0; lst = {}; While[p < 3200000, If[s == p, AppendTo[lst, p]; Print[p]]; s = s + Total@ IntegerDigits[p, 3]; p = NextPrime[p]] (* Robert G. Wilson v, Jul 27 2014 *)


PROG

(PARI) sdt(n) = my(d = digits(n, 3)); sum(i=1, #d, d[i]);
lista(nn) = {sp = 0; forprime(p=1, nn, if (p == sp, print1(p, ", ")); sp += sdt(p); ); } \\ Michel Marcus, May 02 2014


CROSSREFS

Cf. A239619 (Base 3 sum of digits of prime(n)).
Sequence in context: A258578 A031924 A257528 * A162587 A033216 A139837
Adjacent sequences: A240883 A240884 A240885 * A240887 A240888 A240889


KEYWORD

nonn,base,more


AUTHOR

Anthony Sand, Apr 14 2014


STATUS

approved



