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A245475
Numbers n such that the sum of digits, sum of squares of digits, and sum of cubes of digits are all prime.
1
11, 101, 110, 111, 113, 131, 146, 164, 166, 199, 223, 232, 289, 298, 311, 322, 335, 337, 346, 353, 355, 364, 373, 388, 416, 436, 449, 461, 463, 494, 533, 535, 553, 566, 614, 616, 634, 641, 643, 656, 661, 665, 733, 829, 838, 883, 892, 919, 928, 944, 982, 991, 1001, 1010, 1011, 1013, 1031, 1046, 1064, 1066, 1099
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
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