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A350420
Primes p such that p*q+q-p is a semiprime, where q is the next prime after p.
1
11, 29, 41, 47, 53, 59, 73, 101, 107, 131, 139, 151, 173, 181, 197, 199, 211, 257, 271, 311, 317, 331, 373, 389, 401, 461, 467, 479, 491, 509, 521, 523, 541, 563, 593, 599, 601, 607, 619, 647, 677, 719, 727, 743, 751, 809, 827, 919, 929, 947, 971, 977, 1013, 1019, 1021, 1033, 1049, 1061, 1063
OFFSET
1,1
LINKS
EXAMPLE
a(3) = 41 is a term because it is prime, the next prime is 43, and 41*43 + 43 - 41 = 1765 = 5*363 is a semiprime.
MAPLE
q:= 2: R:= NULL: count:= 0:
while count < 100 do
p:= q; q:= nextprime(q);
s:= p*q+q-p;
if numtheory:-bigomega(s)=2 then
count:= count+1; R:= R, p;
fi
od:
R;
CROSSREFS
Sequence in context: A279775 A211191 A353043 * A240678 A087693 A106017
KEYWORD
nonn
AUTHOR
J. M. Bergot and Robert Israel, Dec 30 2021
STATUS
approved