

A110934


Difference between 3almostprime(n) and 3almostprime(n+2).


0



10, 8, 9, 8, 3, 14, 14, 3, 6, 7, 13, 14, 5, 4, 7, 6, 3, 16, 20, 7, 4, 6, 8, 9, 6, 3, 8, 8, 6, 13, 17, 10, 6, 6, 11, 11, 6, 6, 2, 3, 3, 8, 11, 6, 4, 7, 17, 17, 15, 18, 9, 6, 7, 6, 6, 3, 2, 10, 12, 6, 8, 7, 7, 7, 6, 7, 5, 3, 2, 5, 6, 20, 24, 8, 6, 7, 10, 8, 6, 10, 7
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OFFSET

1,1


COMMENTS

This is the 3almost prime analog of what A113784 is for semiprimes and what A031131 is for primes. The minimum values in the sequence are 2 because we have, for example, the 3 consecutive 3almost primes 170, 171, 172, so a(39) = A014612(41)  A014612(39) = 172  170 = 2. Equivalently, there are 2 consecutive 1 values of A114403 (3almost prime gaps; first differences of A014612). This happens for elements of A113789 (numbers n such that n, n+1 and n+2 are 3almost primes).


LINKS

Table of n, a(n) for n=1..81.


FORMULA

a(n) = A014612(n+2)  A014612(n).


EXAMPLE

a(1) = 10 because the difference between the first and third 3almost primes is A014612(3)  A014612(1) = 18  8 = 10.
a(2) = A014612(4)  A014612(2) = 20  12 = 8.
a(3) = A014612(5)  A014612(3) = 27  18 = 9.


CROSSREFS

Cf. A014612, A031131, A067813, A113784, A113789, A114403.
Sequence in context: A024134 A180197 A280871 * A291424 A065691 A147974
Adjacent sequences: A110931 A110932 A110933 * A110935 A110936 A110937


KEYWORD

easy,nonn


AUTHOR

Jonathan Vos Post, Jan 21 2006


EXTENSIONS

a(28) corrected by R. J. Mathar, Dec 22 2010


STATUS

approved



