login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 59th year, we have over 358,000 sequences, and we’ve crossed 10,300 citations (which often say “discovered thanks to the OEIS”).

Other ways to Give
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A240886 Primes p equal to the sum in base-3 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 (list; graph; refs; listen; history; text; internal format)
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..n-1} A239619(i).

EXAMPLE

For example, 23 = digit-sum(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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 8 23:23 EST 2022. Contains 358698 sequences. (Running on oeis4.)