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A270639 Fermat pseudoprimes (A001567) that are the sum of three consecutive primes. 1
13741, 16705, 150851, 208465, 249841, 252601, 258511, 410041, 486737, 635401, 1052503, 1082401, 1457773, 1507963, 1579249, 1615681, 2113921, 2184571, 3090091, 3375487, 3726541, 4682833, 4895065, 5044033, 5133201, 6233977, 6255341, 6350941, 6474691, 6912079, 7259161 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
In other words, Fermat pseudoprimes to base 2 of the form p + q + r where p, q and r are consecutive primes.
If a Fermat pseudoprime is the sum of n consecutive primes, it is so obvious that the minimum value of n is 3.
Intersection of A001567 and A034961.
LINKS
EXAMPLE
4567, 4583 and 4591 are consecutive primes and their sum is 13741, a Fermat pseudoprime.
84191, 84199 and 84211 are consecutive primes and their sum is 252601, a Fermat pseudoprime.
PROG
(PARI) isA001567(n) = {Mod(2, n)^n==2 && !ispseudoprime(n) && n > 1}
a034961(n) = my(p=prime(n), q=nextprime(p+1)); p+q+nextprime(q+1);
for(n=1, 200000, if(isA001567(a034961(n)), print1(a034961(n), ", ")));
CROSSREFS
Sequence in context: A236708 A205259 A235184 * A031807 A119730 A204839
KEYWORD
nonn
AUTHOR
Altug Alkan, Mar 20 2016
STATUS
approved

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Last modified March 4 05:23 EST 2024. Contains 370522 sequences. (Running on oeis4.)