A164275 - OEIS

A164275

The absolute value of (the n-th isolated composite minus the n-th isolated prime).

2, 17, 25, 29, 23, 25, 19, 11, 13, 11, 25, 23, 49, 35, 35, 61, 67, 59, 59, 79, 97, 163, 169, 185, 229, 263, 283, 287, 305, 307, 451, 455, 455, 479, 499, 631, 635, 649, 653, 653, 709, 781, 821, 823, 823, 833, 937, 953, 979, 979, 1067, 1073, 1111, 1135, 1145, 1201, 1279

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OFFSET

1,1

COMMENTS

An isolated composite is surrounded by two primes, and therefore an average of a twin prime pair.

LINKS

Table of n, a(n) for n=1..57.

FORMULA

a(n)= |A014574(n)-A007510(n)|.

EXAMPLE

a(1)=abs(4-2)=2, a(2)=abs(6-23)=17.

CROSSREFS