OFFSET
1,9
COMMENTS
LINKS
Bert Dobbelaere, Table of n, a(n) for n = 1..50
EXAMPLE
a(5)=1 because only one pairing is possible: 4+49=53, 16+81=97.
MATHEMATICA
try[lev_] := Module[{j}, If[lev>n, (*Print[soln]; *) cnt++, For[j=1, j<=Length[s[[lev]]], j++, If[ !MemberQ[soln, s[[lev]][[j]]], soln[[lev]]=s[[lev]][[j]]; try[lev+2]; soln[[lev]]=0]]]]; maxN=28; For[lst2={1}; n=2, n<=maxN, n++, s=Table[{}, {n}]; For[i=2, i<=n, i=i+2, For[j=n+1, j<=2n, j++, If[PrimeQ[i^2+j^2], AppendTo[s[[i]], j]]]]; soln=Table[0, {n}]; cnt=0; try[2]; AppendTo[lst2, cnt]]; lst2
CROSSREFS
KEYWORD
nonn
AUTHOR
T. D. Noe, Nov 15 2002
EXTENSIONS
a(29)-a(46) from Bert Dobbelaere, Sep 08 2019
STATUS
approved