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A341650 a(n) is the first prime p such that each of the first n primes divides at least one of the composites between p and the next prime. 2
2, 3, 5, 7, 13, 19, 61, 113, 113, 113, 113, 113, 773, 773, 773, 887, 887, 2477, 2477, 2477, 2477, 2477, 30727, 31397, 31397, 31397, 31397, 31397, 31397, 155921, 155921, 155921, 221327, 221327, 265621, 265621, 544279, 544279, 1242643, 1242643, 1242643, 1444309, 1444309, 1444309, 1561919, 1561919 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

Robert Israel, Table of n, a(n) for n = 0..86

EXAMPLE

a(6) = 61 because each of the first 6 primes 2,3,5,7,11,13 divides at least one of the composites 62 to 66: 2|62, 3|63, 5|65, 7|63, 11|66 and 13|65.

MAPLE

N:= 50: # for a(0) to a(N)

P:= [seq(ithprime(i), i=1..N)]:

V:= Array(0..N): V[0]:= 2: q:= 3: m:= 0:

while m < N do

  p:= q; q:= nextprime(p);

  E:= mul(i, i=p+1..q-1);

  for r from 1 to N do if E mod P[r] <> 0 then break fi od;

r:= r-1;

  if r > m then

    for s from m+1 to r do V[s]:= p od;

    m:= r;

  fi;

od:

convert(V, list);

CROSSREFS

Sequence in context: A330383 A146999 A147485 * A341640 A104189 A301776

Adjacent sequences:  A341647 A341648 A341649 * A341651 A341652 A341653

KEYWORD

nonn

AUTHOR

J. M. Bergot and Robert Israel, Feb 16 2021

STATUS

approved

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Last modified June 13 00:04 EDT 2021. Contains 344980 sequences. (Running on oeis4.)