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A108257 Numbers n such that concatenating n and the sum of factorials of the digits of n produces a prime. 0

%I

%S 1,13,15,30,31,91,101,110,128,133,136,138,144,152,156,166,175,193,199,

%T 203,215,230,250,260,280,281,303,304,306,307,309,315,320,330,331,340,

%U 361,391,412,508,520,550,606,651,661,681,708,712,717,730,750,751,780

%N Numbers n such that concatenating n and the sum of factorials of the digits of n produces a prime.

%C The largest prime I have found pertaining to this sequence is A109016(Fibonacci(9837)) with 2064 digits (not proved prime, only Fermat and Lucas PRP).

%e 193 is in the sequence because 1!+9!+3! = 362887 and 193362887 is prime.

%Y Cf. A061602, A109016.

%K base,nonn

%O 1,2

%A _Jason Earls_, Jun 18 2005

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Last modified August 10 13:12 EDT 2022. Contains 356039 sequences. (Running on oeis4.)