OFFSET
1,3
COMMENTS
Entries are not repeated and shown in natural order.
EXAMPLE
n=4: 4-(11-3)/(7-5)=0=a(1).
n=6: 6-(17-7)/(13-11)=1=a(2).
n=9: 9-(29-17)/(23-19)=6=a(4).
n=10: 10-(31-19)/(29-23)=8=a(5).
n=11: 11-(37-23)/(31-29)=4=a(3).
MATHEMATICA
Select[PrimePi[#[[3]]]-(#[[4]]-#[[1]])/(#[[3]]-#[[2]])&/@ Partition[ Prime[ Range[200]], 4, 1], IntegerQ[#]&&!PrimeQ[#]&]//Union (* Harvey P. Dale, Jul 06 2017 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Juri-Stepan Gerasimov, Sep 10 2008
EXTENSIONS
Corrected and extended by R. J. Mathar, Sep 26 2008
STATUS
approved