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A049711 n-prevprime(n). 21
1, 1, 2, 1, 2, 1, 2, 3, 4, 1, 2, 1, 2, 3, 4, 1, 2, 1, 2, 3, 4, 1, 2, 3, 4, 5, 6, 1, 2, 1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 1, 2, 1, 2, 3, 4, 1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 5, 6, 1, 2, 1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 1, 2, 1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 5, 6 (list; graph; refs; listen; history; text; internal format)
OFFSET

3,3

COMMENTS

All runs end in even numbers at a(p), new highs are found at A000101 and the increasing gap size is A005250. - Robert G. Wilson v, Dec 07 2001

All terms are positive since here the variant 2 (A151799(n) < n) of the prevprime function is used, rather than the variant 1 (A007917(n) <= n). - M. F. Hasler, Sep 09 2015

LINKS

Table of n, a(n) for n=3..95.

MAPLE

with(numtheory); A049711 := n-> n-prevprime(n);

MATHEMATICA

PrevPrim[n_] := Block[ {k = n - 1}, While[ !PrimeQ[k], k-- ]; Return[k]]; Table[ n - PrevPrim[n], {n, 3, 100} ]

Array[#-NextPrime[#, -1]&, 100, 3] (* Harvey P. Dale, Dec 07 2011 *)

PROG

(PARI) A049711(n)=n-precprime(n-1) \\ M. F. Hasler, Sep 09 2015

CROSSREFS

Cf. A049613, A049653, A049716, A049847.

Cf. A151799, A007917.

Sequence in context: A160975 A305300 A175851 * A137293 A177803 A274080

Adjacent sequences:  A049708 A049709 A049710 * A049712 A049713 A049714

KEYWORD

nonn

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified February 15 20:32 EST 2019. Contains 320138 sequences. (Running on oeis4.)