A283270 Smallest b-a such that a < prime(n)^3 < b, where a,b are semiprimes.

3, 7, 6, 5, 4, 4, 4, 14, 11, 9, 6, 8, 4, 6, 5, 8, 8, 15, 8, 10, 19, 9, 20, 4, 8, 4, 11, 10, 16, 8, 11, 11, 6, 16, 5, 17, 11, 8, 12, 8, 12, 12, 7, 8, 8, 5, 6, 11, 11, 8, 5, 4, 14, 6, 19, 16, 14, 4, 20, 8, 16, 6, 6, 14, 16, 6, 4, 20, 22, 6, 16, 12, 24, 7, 21, 14

Offset

1,1

Comments

This is the third sequence of the series defined in A283267.

Links

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Mathematica

Table[Module[{m = Prime[n]^3, a, b}, a = m - 1; b = m + 1; While[PrimeOmega@ a != 2, a--]; While[PrimeOmega@ b != 2, b++]; b - a], {n, 120}] (* Michael De Vlieger, Mar 04 2017 *)

Prog

(PARI) issemi(n)=bigomega(n)==2
a(n, p=prime(n))=my(a=p^3, b=p^3); while(!issemi(a--), ); while(!issemi(b++), ); b-a \\ Charles R Greathouse IV, Mar 06 2017

Crossrefs

Cf. A283267, A283268.

Sequence in context: A256848 A019952 A157699 * A159779 A188734 A021883

Adjacent sequences: A283267 A283268 A283269 * A283271 A283272 A283273

Keyword

nonn

Author

Vladimir Shevelev, Mar 04 2017

Extensions

More terms from Peter J. C. Moses, Mar 04 2017

Status

approved