A027564 Numbers not of form abcd + abce + abde + acde + bcde for 1 <= a <= b <= c <= d <= e.

1, 2, 3, 4, 6, 7, 8, 10, 11, 12, 14, 15, 18, 19, 20, 22, 24, 26, 27, 31, 32, 34, 35, 36, 38, 39, 42, 46, 47, 50, 54, 55, 59, 60, 62, 66, 67, 70, 71, 75, 78, 84, 87, 90, 92, 94, 98, 99, 102, 104, 106, 110, 111, 115, 116, 119, 122, 126, 127, 130, 131, 132, 138

Offset: 1

Author

R. H. Hardin

Keywords

• nonn
• fini

Links

• Robert Israel, Table of n, a(n) for n = 1..1578

Crossrefs

Cf. A025052 (3 variables), A027563 (4 variables), A027565, A027566.

Programs

Maple

N := 1000: # for all terms <= N
V:= Vector(N):
for a from 1 to floor((N/5)^(1/4)) do
  for b from a while 4*a*b^3+b^4<= N do
    for c from b while 3*a*b*c^2 + (a+b)*c^3 <= N do
      for d from c while 2*a*b*c*d + (b*c+a*c+a*b)*d^2 <= N do
        for e from d do
          r:= a*b*c*d+a*b*c*e+a*b*d*e+a*c*d*e+b*c*d*e;
          if r > N then break fi;
          V[r]:= 1;
od od od od od:
select(t -> V[t]=0, [$1..N]); # Robert Israel, Nov 04 2018