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A285096 Primes with integer arithmetic mean of digits = 2 in base 10. 6

%I #14 Sep 08 2022 08:46:19

%S 2,13,31,1061,1151,1223,1511,1601,2141,2213,2411,3023,3041,3203,3221,

%T 4013,4211,5003,5021,6011,6101,7001,10009,10243,10333,10513,10531,

%U 10711,11071,11161,11251,11503,11701,12007,12043,12241,12421,12511,12601,13033,13411

%N Primes with integer arithmetic mean of digits = 2 in base 10.

%H Jaroslav Krizek, <a href="/A285096/b285096.txt">Table of n, a(n) for n = 1..1000</a>

%p S:= proc(d,k,flag) option remember;

%p if d = 1 then

%p if k >= 0 and k <= 9 then return [k]

%p else return []

%p fi

%p fi;

%p [seq(op(map(`+`, procname(d-1,k-i,0), i*10^(d-1))),i=flag..min(k,9))]

%p end proc:

%p seq(op(select(isprime,S(d,2*d,1))),d=1..5);# _Robert Israel_, Apr 23 2017

%t Select[Prime[Range[1600]],Mean[IntegerDigits[#]]==2&] (* _Harvey P. Dale_, Aug 07 2021 *)

%o (Magma) [n: n in [1..100000] | IsPrime(n) and &+Intseq(n) mod #Intseq(n) eq 0 and &+Intseq(n) / #Intseq(n) eq 2]

%Y Primes in A061385. Subsequence of A069709.

%Y Sequences of primes such that a(n) = k for k = 1, 2, 4, 5, 7 and 8: A069710 (k = 1), this sequence (k = 2), A285225 (k = 4), A285226 (k = 5), A285227 (k = 7), A285228 (k = 8).

%K nonn,base

%O 1,1

%A _Jaroslav Krizek_, Apr 16 2017

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Last modified April 19 07:35 EDT 2024. Contains 371782 sequences. (Running on oeis4.)