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A013638 a(n) = prevprime(n)*nextprime(n). 5
10, 15, 21, 35, 55, 77, 77, 77, 91, 143, 187, 221, 221, 221, 247, 323, 391, 437, 437, 437, 551, 667, 667, 667, 667, 667, 713, 899, 1073, 1147, 1147, 1147, 1147, 1147, 1271, 1517, 1517, 1517, 1591, 1763, 1927 (list; graph; refs; listen; history; text; internal format)
OFFSET

3,1

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 3..10000

FORMULA

a(n)  = A151799(n)*A151800(n). - Reinhard Zumkeller, May 22 2015

MAPLE

[ seq(prevprime(i)*nextprime(i), i=3..70) ];

MATHEMATICA

a[n_] := NextPrime[n, -1] NextPrime[n];

Table[a[n], {n, 3, 50}] (* Jean-Fran├žois Alcover, Aug 02 2018 *)

PROG

(Haskell)

a013638 n = a151799 n * a151800 n  -- Reinhard Zumkeller, May 22 2015

CROSSREFS

Cf. A151799, A151800, A030664.

Sequence in context: A129496 A075520 A030663 * A075524 A048028 A048045

Adjacent sequences:  A013635 A013636 A013637 * A013639 A013640 A013641

KEYWORD

nonn

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified May 30 18:07 EDT 2020. Contains 334728 sequences. (Running on oeis4.)