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A164275 The absolute value of (the n-th isolated composite minus the n-th isolated prime). 0
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 (list; graph; refs; listen; history; text; internal format)
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

Cf. A007510, A014574.

Sequence in context: A049562 A107137 A086322 * A284646 A270344 A300134

Adjacent sequences:  A164272 A164273 A164274 * A164276 A164277 A164278

KEYWORD

nonn

AUTHOR

Juri-Stepan Gerasimov, Aug 11 2009

EXTENSIONS

Entries checked by R. J. Mathar, Aug 27 2009

STATUS

approved

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Last modified January 17 20:36 EST 2020. Contains 330987 sequences. (Running on oeis4.)