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A097824 Gaps associated with the arithmetic progressions of semiprimes in A096003. 5
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 (list; graph; refs; listen; history; text; internal format)
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: A125509 A281251 A247511 * A118877 A112124 A268916

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

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Last modified October 17 13:57 EDT 2019. Contains 328113 sequences. (Running on oeis4.)