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
Keywords
Links
- Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
Programs
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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 *) -
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
Extensions
More terms from Peter J. C. Moses, Mar 04 2017
Comments