OFFSET
1,2
EXAMPLE
1+2+3+10=16, 4+5+6+21=36, 7+8+9+12=36, 11+13+14+26=64.
MATHEMATICA
s={}; ra=Range[2000]; Do[su=ra[[1]]+ra[[2]]+ra[[3]]; c=4; While[ !IntegerQ[Sqrt[su+ra[[c]]]], c++ ]; rac=ra[[c]]; s=Join[s, {ra[[1]], ra[[2]], ra[[3]], rac}]; ra=Complement[ra, {ra[[1]], ra[[2]], ra[[3]], rac}], {50}]; s
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov, May 08 2007
STATUS
approved