OFFSET
1,3
LINKS
Jason Kimberley, Table of n, a(n) for n = 1..10000
FORMULA
MAPLE
A000720 := proc(n) numtheory[pi](n) ; end proc: A167657 := proc(nmax) local ol, a ; ol := 0 ; a := 0 ; for n from 1 to nmax do if A000720(n) = ol then a := a*ol ; else printf("%d, ", a) ; a := A000720(n) ; end if; ol := A000720(n) ; end do ; return ; end proc: A167657(160) ; # R. J. Mathar, Jan 30 2010
MATHEMATICA
Most@ Map[Times @@ # &, Split@ Array[PrimePi, 132]] (* Michael De Vlieger, May 27 2018 *)
PROG
(Magma) A40:=NthPrime;
A167657:=func<n|(n-1)^(A40(n)-A40(n-1))>;
[A167657(n):n in[1..32]]; // Jason Kimberley, May 27 2018
CROSSREFS
KEYWORD
nonn,look
AUTHOR
Giovanni Teofilatto, Nov 08 2009
EXTENSIONS
a(1) = 0 and a(5) = 256 corrected by Giovanni Teofilatto, Nov 12 2009
a(17) inserted and a(20) corrected by R. J. Mathar, Jan 30 2010
Name edited by Jason Kimberley, Jul 01 2018
STATUS
approved