A097824 Gaps associated with the arithmetic progressions of semiprimes in A096003.

12, 12, 4, 52, 52, 72, 96, 198, 198, 114, 594, 48, 354, 1860, 3942, 2574, 2574, 2574, 20910, 20910, 9600, 9600, 152250, 152250, 152250, 152250, 1887270, 4667040, 4094790

Offset

4,1

Comments

The terms a(1),a(2) and a(3) are omitted to avoid the ambiguity caused by the two progressions of length 3 ending at A096003(3)=14: a(3)=5 for (4,9,14) or a(3)=4 for (6,10,14).

Links

Table of n, a(n) for n=4..32.

Example

a(6)=4 because the 6 semiprimes in the progression ending at A096003(6)=221 are separated by an increment of 4: 201=3*67, 205=5*41, 209=11*19, 213=3*71, 217=7*31, 221=13*17.

Crossrefs

Cf. A096003, A093364 gaps in arithmetic progressions of primes, A082919 clusters of 8 consecutive semiprimes.

Sequence in context: A281251 A247511 A374989 * A133208 A118877 A112124

Adjacent sequences: A097821 A097822 A097823 * A097825 A097826 A097827

Keyword

more,nonn

Author

Hugo Pfoertner, Aug 27 2004

Extensions

a(26)-a(30) from Hugo Pfoertner, Sep 07 2004

a(31)-a(32) from Donovan Johnson, Jun 03 2012

Status

approved