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
Examples
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]).
Links
- Robert Israel, Table of n, a(n) for n = 1..10000
Crossrefs
Programs
-
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 *) -
PARI
for(n=1,33,print1(nextprime(n^2)*precprime((n+1)^2),", ")) \\ Hugo Pfoertner, Jan 26 2020
Extensions
More terms from Stefan Steinerberger, Nov 20 2007