OFFSET
1,2
COMMENTS
Range of A000688.
LINKS
David W. Wilson, Table of n, a(n) for n = 1..10000
MAPLE
with(combinat): A000041:=proc(n) options remember: RETURN(numbpart(n)): end: partdiv:=proc(m, i) local j, q, f: f:=0: for j from i by -1 to 2 while(f=0) do if(irem(m, A000041(j))=0) then q:=iquo(m, A000041(j)): if(q=1) then RETURN(1) else f:=partdiv(q, j) fi fi od: RETURN(f): end: for i from 2 to 15 do for n from A000041(i) to A000041(i+1)-1 do m:=partdiv(n, i): if m=1 then printf("%d, ", n) fi od od: # C. Ronaldo
MATHEMATICA
p0 = Table[ PartitionsP[n], {n, 1, 40 (* ~ 1148 terms *)}] ; f[p_] := Select[ Outer[Times, p, p] // Flatten // Union, # <= Last[p0] &]; FixedPoint[f, p0] (* Jean-François Alcover, Oct 03 2013 *)
PROG
(PARI) is(n, mx=n)=if(n>>valuation(n, 2)==1, return(1)); for(i=3, n, my(p=numbpart(i), m=n); while(m%p==0, if(is(m/=p), return(1))); if(p>n, return(0))) \\ Charles R Greathouse IV, Jun 28 2013
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
EXTENSIONS
More terms from C. Ronaldo (aga_new_ac(AT)hotmail.com), Jan 02 2005
STATUS
approved