A132657 a(n) is the product of the least prime > n^2 and the greatest prime < (n+1)^2.

6, 35, 143, 391, 899, 1739, 3233, 5293, 8051, 11413, 17653, 24883, 33389, 43931, 56977, 72731, 92881, 118829, 145699, 176039, 212197, 254701, 308911, 357163, 424663, 492179, 566609, 660293, 756611, 864371, 987307, 1120697, 1257923

Offset

1,1

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Formula

a(n) = A007491(n) * A053001(n+1).

Example

a(1) = 6 = 2*3 = (smallest prime in [1^2,2^2]) * (largest prime in [1^2,2^2]).
a(2) = 35 = 5*7 = (smallest prime in [2^2,3^2]) * (largest prime in [2^2,3^2]).

Maple

seq(nextprime(n^2)*prevprime((n+1)^2, n=1..100); # Robert Israel, Jan 26 2020

Mathematica

Table[Prime[PrimePi[n^2] + 1]*Prime[PrimePi[(n + 1)^2]], {n, 1, 40}] (* Stefan Steinerberger, Nov 20 2007 *)
NextPrime[#[[1]]]NextPrime[#[[2]], -1]&/@Partition[Range[40]^2, 2, 1] (* Harvey P. Dale, Aug 27 2022 *)

Prog

(PARI) for(n=1, 33, print1(nextprime(n^2)*precprime((n+1)^2), ", ")) \\ Hugo Pfoertner, Jan 26 2020

Crossrefs

Cf. A000040, A001358, A007491, A014085, A053000, A053001, A053607, A077766, A077767, A132435.

Sequence in context: A024526 A213504 A089581 * A161784 A027985 A078799

Adjacent sequences: A132654 A132655 A132656 * A132658 A132659 A132660

Keyword

easy,nonn

Author

Jonathan Vos Post, Nov 15 2007

Extensions

More terms from Stefan Steinerberger, Nov 20 2007

Status

approved