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A161182 Successive differences between positions of squares in list of nonprimes. 2
1, 1, 3, 5, 6, 9, 9, 12, 13, 16, 16, 19, 20, 22, 25, 25, 26, 30, 31, 33, 34, 36, 38, 41, 40, 43, 46, 47, 48, 51, 53, 53, 56, 57, 60, 61, 64, 66, 65, 68, 69, 72, 76, 75, 78, 78, 83, 82, 82, 89, 90, 88, 89, 95, 96, 100, 101, 98, 104, 103, 105, 110, 108, 112, 115, 115, 118, 120 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,3
LINKS
FORMULA
a(n) = A078435(n) - A078435(n-1). - R. J. Mathar, Jun 22 2009
MAPLE
A038107 := proc(n) numtheory[pi]( n^2) ; end: A078435 := proc(n) n^2-A038107(n) ; end: A161182 := proc(n) A078435(n)-A078435(n-1) ; end: seq(A161182(n), n=1..100) ; # R. J. Mathar, Jun 22 2009
MATHEMATICA
With[{nn=5000}, Differences[Flatten[Position[Complement[Range[0, nn], Prime[ Range[ PrimePi[nn]]]], _?(IntegerQ[Sqrt[#]]&)]]]] (* Harvey P. Dale, Mar 03 2014 *)
CROSSREFS
Cf. A078435, sequence of positions of squares in sequence of nonprimes.
Sequence in context: A199187 A098587 A321885 * A267312 A362579 A331386
KEYWORD
nonn
AUTHOR
Daniel Tisdale, Jun 05 2009
EXTENSIONS
Corrected and extended by R. J. Mathar, Jun 22 2009
STATUS
approved

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Last modified March 19 03:21 EDT 2024. Contains 370952 sequences. (Running on oeis4.)