OFFSET
1,2
COMMENTS
Trivially, no prime number can be a semiperimeter of an integer Heronian triangle. Therefore primes are excluded from the sequence.
LINKS
Eric Weisstein's World of Mathematics, Heronian Triangle.
MAPLE
notriangle:=proc(n::nonnegint) local a, b, c; if type(n, prime) then RETURN(false) fi; for a from floor(2*n/3) to n-1 do for b from floor(n-a/2) to a do c:=2*n-a-b; if type(sqrt(n*(n-a)*(n-b)*(n-c)), integer) then RETURN(false); fi; od; od; RETURN(true); end: N:=100: a:=array[1..N]: i:=0: n:=0: while i<N do n:=n+1; if notriangle(n) then i:=i+1; a[i]:=n; fi; od: seq(a[i], i=1..N);
CROSSREFS
KEYWORD
nonn
AUTHOR
Seppo Mustonen, Jan 17 2007
STATUS
approved