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A084195 Even numbers n such that the sum of the digits is prime, n/2 is prime and the sum of the digits of n/2 is also prime. 0

%I

%S 14,58,94,122,166,274,278,302,346,382,386,454,458,526,562,566,634,674,

%T 706,746,818,922,926,1114,1154,1198,1202,1282,1286,1466,1514,1594,

%U 1642,1646,1774,1822,1954,2038,2078,2102,2182,2186,2218,2258,2326,2362

%N Even numbers n such that the sum of the digits is prime, n/2 is prime and the sum of the digits of n/2 is also prime.

%e 5+8=13 for n=58 and 2+9=11 for n/2=29=prime.

%e 1+2+2=5 for n=122 and 6+1=7 for n/2=61=prime.

%e 2+7+8=17 for n=278 and 1+3+9=13 for n/2=139=prime.

%o (PARI) isok(n) = {if (n % 2, return (0)); dn = digits(n); dh = digits(n/2); isprime(n/2) && isprime(sum(i=1, #dn, dn[i])) && isprime(sum(i=1, #dh, dh[i]));} \\ _Michel Marcus_, Aug 12 2013

%Y Subsequence of A084194.

%K base,nonn

%O 1,1

%A _Patrick Capelle_, Jun 20 2003

%E More terms from _Michel Marcus_, Aug 12 2013

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Last modified September 18 09:40 EDT 2019. Contains 327168 sequences. (Running on oeis4.)