A178045 Numbers of semiprimes between consecutive even numbers that are not semiprimes.

0, 2, 2, 2, 0, 0, 2, 2, 0, 0, 3, 2, 0, 0, 1, 1, 1, 0, 1, 2, 1, 1, 0, 1, 0, 1, 1, 0, 1, 3, 0, 1, 3, 0, 0, 0, 0, 1, 0, 1, 0, 1, 2, 3, 0, 0, 1, 0, 2, 0, 0, 3, 2, 0, 0, 0, 1, 2, 1, 0, 1, 1, 0, 0, 0, 2, 0, 1, 1, 1, 0, 0, 1, 0, 0, 3, 2, 1, 0, 3, 3, 1, 0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 0, 1, 1, 0, 2, 0, 1, 1, 1, 1, 0, 0, 1

Offset

1,2

Comments

Numbers of semiprimes between A176100(n) and A176100(n+1) where A176100 is twice the n-th nonprime numbers.

Links

Table of n, a(n) for n=1..105.

Example

a(1)=0 because 2*A141468(1)=0<2=2*A141468(2); a(2)=2 because 2*A141468(2)=2<4(semiprime)<6(semiprime)<8=2*A141468(3).

Crossrefs

Cf. A001358, A141468, A176851.

Sequence in context: A257921 A261119 A004541 * A321300 A037864 A285635

Adjacent sequences: A178042 A178043 A178044 * A178046 A178047 A178048

Keyword

nonn

Author

Juri-Stepan Gerasimov, May 18 2010

Extensions

a(66) and a(67) corrected by R. J. Mathar, May 28 2010

Status

approved