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A198696 Positions of local maxima in differences of primes, A001223. 2
4, 6, 9, 11, 18, 21, 24, 27, 30, 32, 34, 42, 44, 51, 53, 58, 62, 66, 68, 72, 77, 80, 82, 84, 87, 91, 94, 97, 99, 101, 106, 114, 121, 125, 127, 132, 135, 137, 139, 141, 143, 146, 150, 154, 157, 162, 166, 168, 170, 172, 175, 177, 180, 186, 189, 191, 193, 197 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Or, numbers n such that A001223(n-1) < A001223(n) > A001223(n+1).

Corresponding values of local maxima (4, 4, 6, 6, 6, 6, 8,...) are in A198697.

LINKS

Table of n, a(n) for n=1..58.

MATHEMATICA

nn = 1001; t = Differences[Prime[Range[nn]]]; t2 = {}; Do[If[t[[n - 1]] < t[[n]] && t[[n]] > t[[n + 1]], AppendTo[t2, {n, t[[n]]}]], {n, 2, nn - 2}]; Transpose[t2][[1]] (* T. D. Noe, Dec 27 2011 *)

CROSSREFS

Cf. A196175 local minima in A001223 (first differences of primes), A198697.

Sequence in context: A003259 A020935 A267149 * A219612 A258743 A292660

Adjacent sequences:  A198693 A198694 A198695 * A198697 A198698 A198699

KEYWORD

nonn

AUTHOR

Zak Seidov, Oct 29 2011

STATUS

approved

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Last modified April 18 11:10 EDT 2019. Contains 322209 sequences. (Running on oeis4.)