A035496 Numbers of the form x*y^2 + y*z^2 + z*x^2, x,y,z >= 1.

3, 7, 13, 14, 21, 23, 24, 25, 31, 34, 38, 39, 40, 43, 47, 55, 56, 57, 59, 61, 62, 73, 78, 79, 80, 81, 82, 84, 89, 91, 93, 98, 104, 107, 109, 111, 112, 113, 115, 119, 121, 123, 133, 134, 136, 138, 139, 140, 142, 146, 147, 148, 150, 152, 155, 157, 163, 165, 166, 167

Offset

1,1

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Maple

N:= 1000: # for terms <= N
S:= {}:
for x from 1 while x + x^2 <= N do
  for y from 1 to x while x*y^2 + y + x^2 <= N do
   for z from 1 to x do
       v:= x*y^2 + y*z^2 + z*x^2;
       if v > N then break fi;
       S:= S union {v};
od od od:
sort(convert(S, list)); # Robert Israel, Mar 23 2021

Mathematica

Select[ Union[ Flatten[ Table[ x^2y+y^2z+z^2x, {x, 1, 13}, {y, 1, 13}, {z, 1, 13} ] ] ], #<14^2+14+1& ]

Crossrefs

Sequence in context: A290642 A295009 A310251 * A310252 A056530 A341447

Adjacent sequences: A035493 A035494 A035495 * A035497 A035498 A035499

Keyword

nonn,easy

Author

N. J. A. Sloane

Extensions

More terms from Erich Friedman

Status

approved