A205955 a(n) = prime(n) * (prime(n+2) - prime(n+1)).

4, 6, 20, 14, 44, 26, 68, 114, 46, 174, 124, 74, 164, 258, 282, 106, 354, 244, 134, 426, 292, 474, 664, 356, 194, 404, 206, 428, 1526, 452, 762, 262, 1370, 278, 894, 906, 628, 978, 1002, 346, 1790, 362, 764, 386, 2364, 2388, 844, 446, 908, 1374, 466, 2390

Offset

1,1

Links

Michel Marcus, Table of n, a(n) for n = 1..1000

Example

a(1) = prime(1)*(prime(3) - prime(2)) = 2*(5-3) = 4.
a(2) = prime(2)*(prime(4) - prime(3)) = 3*(7-5) = 6.
a(3) = prime(3)*(prime(5) - prime(4)) = 5*(11-7) = 20.

Maple

A205955:=n->ithprime(n)*(ithprime(n+2)-ithprime(n+1)): seq(A205955(n), n=1..100); # Wesley Ivan Hurt, May 02 2017

Mathematica

#1 (#3 - #2) & @@ # & /@ Partition[Prime@ Range@ 54, 3, 1] (* Michael De Vlieger, May 03 2017 *)

Prog

(PARI) a(n) = prime(n) * (prime(n+2) - prime(n+1)) \\ Michel Marcus, Aug 06 2013

Crossrefs

Cf. A000040, A001223.

Sequence in context: A367864 A354204 A123169 * A023863 A024480 A066193

Adjacent sequences: A205952 A205953 A205954 * A205956 A205957 A205958

Keyword

nonn,easy

Author

Umut Uludag, Feb 02 2012

Status

approved