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A054546 First differences of nonprimes (including 0 and 1, A002808). 8
1, 3, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 1, 1, 1, 1, 2, 2, 1, 1, 1, 1, 2, 1, 1, 2, 2, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 2, 1, 1, 1, 1, 2, 1, 1, 2, 2, 1, 1, 1, 1, 2, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 2, 1, 1, 1, 1, 2 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Sum of first n terms equals n-th nonprime number.

First differences of A141468. - Omar E. Pol, Oct 21 2011

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

FORMULA

a(n) = A018252(n) - A141468(n). - Omar E. Pol, Oct 21 2011

MATHEMATICA

t=Flatten[Position[Table[PrimeQ[w], {w, 2, 256}], False]]+1 Delete[t-RotateRight[t], 1]

Differences[Select[Range[0, 200], !PrimeQ[#]&]] (* Harvey P. Dale, May 27 2018 *)

CROSSREFS

Cf. A141468, A066110, A001223

Sequence in context: A214878 A086138 A170822 * A065310 A226352 A238402

Adjacent sequences:  A054543 A054544 A054545 * A054547 A054548 A054549

KEYWORD

nonn,easy

AUTHOR

G. L. Honaker, Jr., Apr 09 2000

EXTENSIONS

More terms from James A. Sellers, Apr 11 2000

STATUS

approved

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Last modified October 20 02:54 EDT 2019. Contains 328244 sequences. (Running on oeis4.)