[seqfan] smallest odd prime that divides (-n) + sum of all smaller primes
Neil Fernandez
primeness at borve.org
Fri Nov 11 23:22:27 CET 2016
Thanks again, Jack. And we can do it in the other direction:
A274995
a(n) is the smallest odd prime that divides (-n) + the sum of all
smaller primes, or 0 if no such prime exists:
5, 19, 3, 7, 82811, 3, 11, 17, 3, 191, 5, 3, 37, 29, 3, 5, 0, 3, 0,
28463, 3, 431, 0, 3, 7, 5
Neil
In message <40cd3587-ee62-d8c2-fdaa-deaccf977422 at brennen.net>, Jack
Brennen <jfb at brennen.net> writes
>***UPDATING with a(12) value and extending for known values***
>
>I get this, which fills in your missing entries, and corrects one value
>that you omitted:
>
>[5, 3, 30915397, 11339869, 3, 5, 859, 3, 41, 233, 3, 7, 4175194313, 3,
>307, 5, 3, 1459, 7, 3, 5, 9907, 3, 647, 13, 3, 31, 11, 3, 193, 5, 3, 7,
>2939, 3, 5, 3167, 3, 11, 7, 3, 1321, 86629, 3, 17, 5, 3]
>
>a(47) -- the first unknown entry -- would be greater than a(12).
>
>
>
>
>On 11/11/2016 11:44 AM, Neil Fernandez wrote:
>> Hello,
>>
>> A sequence I've just submitted (A274649):
>>
>> a(n) is the smallest odd prime that divides n + the sum of all smaller
>> primes, or 0 if unknown
>>
>> Starting with a(0), the sequence runs
>>
>> 5, 3, 0, 0, 3, 5, 859, 3, 41, 233, 3, 7, 0, 3, 307, 5, 3, 1459, 7, 3, 5,
>> 9907, 3, 13, 3, 31, 11
>>
>> Does a(n) exist for all n?
>> If a(2) or a(3) exists, it is greater than 600000.
>>
>> Neil
>>
>>
>> --
>> Seqfan Mailing list - http://list.seqfan.eu/
>>
>>
>>
>
--
Neil Fernandez
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