A176179 Primes such that the sum of digits, the sum of the squares of digits and the sum of 3rd powers of their digits is also a prime.
11, 101, 113, 131, 199, 223, 311, 337, 353, 373, 449, 461, 463, 641, 643, 661, 733, 829, 883, 919, 991, 1013, 1031, 1103, 1301, 1439, 1451, 1471, 1493, 1499, 1697, 1741, 1949, 2089, 2111, 2203, 2333, 2441, 2557, 3011, 3037, 3307, 3323, 3347, 3491, 3583, 3637, 3659, 3673, 3853, 4049, 4111, 4139, 4241, 4337, 4373, 4391, 4409
Offset: 1
Examples
For the prime number n =5693 we obtain : 5 + 6 + 9 + 3 = 23 ; 5^2 + 6^2 + 9^2 + 3^2 = 151 ; 5^3 + 6^3 + 9^3 + 3^3 = 1097.
References
- Charles W. Trigg, Journal of Recreational Mathematics, Vol. 20(2), 1988.
Links
- Michael S. Branicky, Table of n, a(n) for n = 1..10000
- Mike Mudge, Morph code, Hands On Numbers Count, Personal Computer World, May 1997, p. 290.
Programs
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Maple
with(numtheory):for n from 2 to 10000 do:l:=evalf(floor(ilog10(n))+1):n0:=n:s1:=0:s2:=0:s3:=0:for m from 1 to l do:q:=n0:u:=irem(q,10):v:=iquo(q,10):n0:=v :s1:=s1+u:s2:=s2+u^2:s3:=s3+u^3:od:if type(n,prime)=true and type(s1,prime)=true and type(s2,prime)=true and type(s3,prime)=true then print(n):else fi:od:
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Mathematica
okQ[n_]:=Module[{idn=IntegerDigits[n]}, And@@PrimeQ[Total/@{idn,idn^2,idn^3}]]; Select[Prime[Range[600]],okQ] (* Harvey P. Dale, Jan 18 2011 *)
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Python
from sympy import isprime, primerange def ok(p): return all(isprime(sum(int(d)**k for d in str(p))) for k in [1, 2, 3]) def aupto(limit): return [p for p in primerange(1, limit+1) if ok(p)] print(aupto(4409)) # Michael S. Branicky, Nov 23 2021
Extensions
Corrected and extended by Harvey P. Dale, Jan 18 2011
Comments