A045881 Smallest of first string of exactly 2n-1 consecutive composite integers.

4, 8, 24, 90, 140, 200, 114, 1832, 524, 888, 1130, 1670, 2478, 2972, 4298, 5592, 1328, 9552, 30594, 19334, 16142, 15684, 81464, 28230, 31908, 19610, 35618, 82074, 44294, 43332, 34062, 89690, 162144, 134514, 173360, 31398, 404598, 212702, 188030, 542604

Offset

1,1

Links

Donovan Johnson, Table of n, a(n) for n = 1..672 (from Nicely link)

Thomas R. Nicely, First occurrence prime gaps [For local copy see A000101]

Mathematica

Reap[For[k=2, k <= 80, k = k+2, p=3; q=5; While[q-p != k, p=q; q=NextPrime[p+1]]; Print[p+1]; Sow[p+1]]][[2, 1]] (* Jean-François Alcover, May 17 2013, after Klaus Brockhaus *)
With[{cmps=Table[If[CompositeQ[n], 1, 0], {n, 10^6}]}, Flatten[Table[ SequencePosition[ cmps, Join[{0}, PadRight[{}, i, 1], {0}], 1], {i, 1, 81, 2}], 1][[All, 1]]+1] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, May 02 2017 *)

Prog

(PARI) forstep(k=2, 80, 2, p=3; q=5; while(q-p!=k, p=q; q=nextprime(p+1)); print1(p+1, ", ")) \\ Klaus Brockhaus, Jan 24 2008

Crossrefs

Equals A000230(n) + 1.

Sequence in context: A240530 A303882 A008950 * A303989 A052578 A066631

Adjacent sequences: A045878 A045879 A045880 * A045882 A045883 A045884

Keyword

nonn,nice

Author

Erich Friedman

Extensions

More terms from Harvey P. Dale, Jul 27 2001

Status

approved