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A045881 Smallest of first string of exactly 2n-1 consecutive composite integers. 8
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 (list; graph; refs; listen; history; text; internal format)
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-Fran├žois 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

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Last modified November 27 07:28 EST 2021. Contains 349365 sequences. (Running on oeis4.)