A271233 - OEIS

%I #7 May 15 2022 13:41:17

%S 90,91,92,93,94,95,96,360,361,362,363,364,365,366,390,391,392,393,394,

%T 395,396,402,403,404,405,406,407,408,450,451,452,453,454,455,456,480,

%U 481,482,483,484,485,486,492,493,494,495,496,497,498,684,685,686,687,688,689,690

%N Composite integers sandwiched between primes p, q with q-p = 8.

%H Laurent Coppey, <a href="http://www.numdam.org/item?id=DIA_2011__65-66__1_0">Décompositions multiplicatives directes des entiers</a>, Diagrammes, 65-66 (2011), p. 1-68, in French, see J8 p. 11.

%e The composite number 90 is sandwiched between consecutive primes 89 and 97, and 97-89=8, so 90 is a member of the sequence.

%t Range[#[[1]]+1,#[[2]]-1]&/@Select[Partition[Prime[Range[150]],2,1],#[[2]]-#[[1]] == 8&]//Flatten (* _Harvey P. Dale_, May 15 2022 *)

%o (PARI) lista(nn) = {forcomposite(c=4, nn, if ((p=precprime(c)) && ((nextprime(c)-p)==8), print1(c, ", ")););}

%Y Cf. A014574, A031926, A045881, A271211, A271232.

%K nonn

%O 1,1

%A _Michel Marcus_, Apr 02 2016