A350324 Missing even distances in full prime rulers, i.e., even numbers k, 0 < k < p-3 for some prime p, such that k is not the difference of two primes less than or equal to p.
88, 112, 118, 140, 182, 202, 214, 242, 284, 292, 298, 316, 322, 338, 358, 388, 400, 410, 422, 448, 470, 478, 490, 512, 526, 532, 548, 578, 622, 632, 664, 682, 692, 700, 710, 718, 742, 760, 772, 778, 788, 800, 812, 830, 838, 844, 862, 868, 886, 892, 898, 910, 920, 928, 952, 958, 982, 1000, 1022, 1040, 1052, 1072, 1078, 1108, 1130, 1136, 1142, 1154, 1162, 1172, 1192, 1204
Offset: 1
Keywords
Examples
a(1) = 88 < p - 3 for prime number p = 97, and there are no primes p1, p2 <= p with 88 = p1 - p2.
Programs
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Maple
primedist := n -> {seq(2*j, j = 0..(ithprime(n) - 3)/2)} minus `union`(seq({seq(abs(ithprime(j) - ithprime(k)), k = 1..j)}, j = 1..n)): `union`(seq(primedist(j), j = 1..200)); # Peter Luschny, Dec 24 2021 -
PARI
genit(maxx=1300)={arr=List();forstep(x=2,maxx,2,q=nextprime(x+2);if(!isprime(q-x),listput(arr,x)));arr;} \\ Bill McEachen, Feb 09 2022
Comments