A198696 Positions of local maxima in differences of primes, A001223.

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

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