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A055514 Composite numbers that are the sum of a string of consecutive prime numbers and are divisible by the first and last primes. 6

%I

%S 10,39,155,371,10225245560,2935561623745,454539357304421,

%T 7228559051256366318,1390718713078158117206

%N Composite numbers that are the sum of a string of consecutive prime numbers and are divisible by the first and last primes.

%C Composite n such that n = p_1 + p_2 + ... + p_k where the p_i are consecutive primes and n is divisible by p_1 and p_k.

%C No more terms below 10^22. - _Michael Beight_, Jul 22 2012

%D Problem proposed by Carlos Rivera, who found first 4 terms.

%H C. Rivera, <a href="http://www.primepuzzles.net/puzzles/puzz_098.htm">Puzzle</a>

%e 503 + 509 + 521+ ... + 508213 = 10225245560, which is divisible by 503 and 508213. - _Manuel Valdivia_, Nov 17 2011

%e From _Michael Beight_, Jul 22 2012: (Start)

%e a(8) = 7228559051256366318 = 73 + ... + 18281691653;

%e a(9) = 1390718713078158117206 = 370794889 + ... + 267902967061. (End)

%Y Cf. A055233.

%K nice,nonn

%O 1,1

%A _Jud McCranie_, Jul 03 2000

%E a(7) from _Donovan Johnson_, Jun 19 2008

%E a(8) and a(9) from _Michael Beight_, Jul 22 2012

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Last modified August 5 21:02 EDT 2021. Contains 346488 sequences. (Running on oeis4.)