OFFSET
1,1
COMMENTS
There are infinitely many numbers in this sequence; 0's can be added to any number any number of times in any logical order (i.e., the number doesn't start with a zero).
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
EXAMPLE
1^1 + 4^1 + 6^1 = 11 is prime.
1^2 + 4^2 + 6^2 = 53 is prime.
1^3 + 4^3 + 6^3 = 281 is prime.
Thus 146, 164, 416, 461, 641, and 614 are members of this sequence.
MAPLE
filter:= proc(n) local L;
L:= convert(n, base, 10);
isprime(convert(L, `+`)) and
isprime(convert(map(`^`, L, 2), `+`)) and
isprime(convert(map(`^`, L, 3), `+`))
end proc:
select(filter, [$1..2000]); # Robert Israel, Dec 04 2024
MATHEMATICA
sdpQ[n_]:=Module[{idn=IntegerDigits[n]}, AllTrue[{Total[idn], Total[ idn^2], Total[ idn^3]}, PrimeQ]]; Select[Range[1100], sdpQ] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Apr 06 2018 *)
PROG
(PARI) for(n=1, 10^3, d=digits(n); s1=sum(i=1, #d, d[i]); s2=sum(j=1, #d, d[j]^2); s3=sum(k=1, #d, d[k]^3); if(isprime(s1)&&isprime(s2)&&isprime(s3), print1(n, ", ")))
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Derek Orr, Jul 23 2014
STATUS
approved
