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A362578 Prime numbers followed by two consecutive numbers which are products of four distinct primes (or tetraprimes). 1

%I #16 Jun 19 2023 10:45:41

%S 8293,16553,17389,18289,22153,26893,29209,33409,35509,36293,39233,

%T 39829,40493,41809,45589,48109,58393,59629,59753,59981,60493,60913,

%U 64013,64921,65713,66169,69221,71329,74093,75577,75853,77689,77933,79393,79609,82913,84533,85853,87589,87701,88681

%N Prime numbers followed by two consecutive numbers which are products of four distinct primes (or tetraprimes).

%e 8293 (prime), 8294 = 2*11*13*29 and 8295 = 3*5*7*79.

%e 16553 (prime), 16554 = 2*3*31*89 and 16555 = 5*7*11*43.

%e 17389 (prime), 17390 = 2*5*37*47 and 17391 = 3*11*17*31.

%t q[n_] := FactorInteger[n][[;; , 2]] == {1, 1, 1, 1}; Select[Prime[Range[10^4]], AllTrue[# + {1, 2}, q] &] (* _Amiram Eldar_, Apr 25 2023 *)

%o (PARI) is(n) = (omega(n)==4) && (bigomega(n)==4); \\ A046386

%o isok(p) = isprime(p) && is(p+1) && is(p+2); \\ _Michel Marcus_, Apr 25 2023

%Y Cf. A000040, A046386, A140078 and A361796.

%K nonn

%O 1,1

%A _Massimo Kofler_, Apr 25 2023

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Last modified August 4 05:35 EDT 2024. Contains 374905 sequences. (Running on oeis4.)