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%I #9 Jun 13 2016 07:00:13
%S 7,19,34,41,53,44,38,103,91,73,99,75,135,142,147,118,133,125,118,193,
%T 229,191,212,202,197,201,216,213,248,239,209,248,279,279,277,277,333,
%U 325,350,327,299,308,264,309,314,322,297,281,363,374,461,488,484,482
%N Prime(3almostprime(n))-3almostprime(prime(n)). Commutator [A000040,A014612] at n.
%C Primes indexed by 3-almost primes = A124268. 3-almost primes indexed by primes = A124269. See also A106349 Primes indexed by semiprimes. See also A106350 Semiprimes indexed by primes.
%H Giovanni Resta, <a href="/A124270/b124270.txt">Table of n, a(n) for n = 1..10000</a>
%F a(n) = prime(3almostprime(n)) - 3almostprime(prime(n)) = A000040(A014612(n)) - A014612(A000040(n)).
%e a(1) = prime(3almostprime(1)) - 3almostprime(prime(1)) = prime(8) - 3almostprime(2) = 19 - 12 = 7.
%e a(2) = prime(3almostprime(2)) - 3almostprime(prime(2)) = prime(12) - 3almostprime(3) = 37 - 18 = 19.
%e a(3) = prime(3almostprime(3)) - 3almostprime(prime(3)) = prime(18) - 3almostprime(5) = 61 - 27 = 34.
%o (PARI) lista(nn) = {p = primes(nn); pp = select(x->bigomega(x)==3, vector(nn, n, n)); for (n=1, nn, print1(p[pp[n]] - pp[p[n]], ", "););} \\ _Michel Marcus_, Oct 15 2014
%Y Cf. A000040 (primes), A014612 (3-almost primes).
%Y Cf. A124268 (prime(3-almost prime(n)), A124269 (3-almost prime(primes(n)).
%Y Cf. A106349 (prime(semiprime(n)), A106350 (semiprime(prime(n)), A122824 (Prime(semiprime(n)) - semiprime(prime(n)).
%K easy,nonn
%O 1,1
%A _Jonathan Vos Post_, Oct 23 2006
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