A376503 Primes p such that p + 2, p + 4 and p + 6 are products of 3, 5 and 7 primes respectively (counted with multiplicity).
171869, 5609369, 7653119, 11177069, 11320709, 11479319, 12325619, 13530119, 15426419, 15558119, 17136619, 17541869, 17851919, 18809369, 18843119, 19593869, 19634369, 19938119, 20806619, 21600419, 22470953, 23637839, 23796869, 23999369, 24006119, 24275819, 25798739, 25879001, 25965869, 26278169
Offset: 1
Keywords
Examples
a(3) = 7653119 is a term because 7653119 is prime, 7653121 = 7 * 61 * 17923 has 3 prime factors, 7653123 = 3^4 * 94483 has 5 prime factors, and 7653125 = 5^5 * 31 * 79 has 7 prime factors, counted with multiplicity.
Links
- Robert Israel, Table of n, a(n) for n = 1..10000
Programs
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Maple
with(priqueue): R:= NULL: count:= 0: initialize(pq): insert([-5^7,[5$7]],pq): for iter from 1 while count < 100 do t:= extract(pq); v:= -t[1]; w:= t[2]; if isprime(v-6) and numtheory:-bigomega(v-4) = 3 and numtheory:-bigomega(v-2) = 5 then R:= R,v-6; count:= count+1; fi; p:= nextprime(w[-1]); for i from 7 to 1 by -1 while w[i] = w[7] do insert([t[1]*(p/w[7])^(8-i),[op(w[1..i-1]),p$(8-i)]],pq); od; od: R;
Comments