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Terms of A025487 from which the distance to the next larger prime is a composite number.
2

%I #7 Dec 24 2019 17:31:40

%S 512,16384,373248,393216,524288,1119744,4194304,4718592,5971968,

%T 8388608,10077696,10616832,17915904,21233664,31104000,33554432,

%U 35831808,42467328,47775744,56623104,67108864,150994944,159252480,286654464,322486272,362797056,679477248,859963392,1528823808,2176782336,2890137600,4294967296,5804752896,8748000000

%N Terms of A025487 from which the distance to the next larger prime is a composite number.

%C From the first 795641 terms of A025487 (terms that are in range 1 .. 2^101) only 4238 (~ 0.5 %) are included in this sequence.

%H Antti Karttunen, <a href="/A329894/b329894.txt">Table of n, a(n) for n = 1..4238</a>

%e As A151800(512) = 521, with 521 - 512 = 9 (a composite number), 512 is included in this sequence.

%o (PARI)

%o isc(n) = ((n > 1)&&!isprime(n));

%o for(n=1,2000,if(isc(nextprime(1+A025487(n))-A025487(n)),print1(A025487(n),", ")));

%Y Cf. A025487, A129912, A141345, A151800.

%K nonn

%O 1,1

%A _Antti Karttunen_, Dec 24 2019