A278647 First differences of Hypotenuse numbers A009003.

5, 3, 2, 2, 3, 5, 1, 3, 1, 4, 1, 2, 2, 1, 1, 4, 5, 1, 1, 1, 2, 3, 2, 1, 4, 3, 2, 3, 1, 1, 3, 2, 2, 3, 2, 2, 1, 1, 4, 2, 3, 1, 1, 2, 1, 1, 3, 1, 1, 2, 2, 1, 1, 2, 1, 2, 1, 2, 5, 5, 1, 1, 3, 3, 2, 1, 2, 1, 1, 3, 2, 1, 1, 2, 1, 4, 1, 4, 1, 3, 1, 1, 3, 2, 1, 1, 1, 2, 2, 3, 3, 1, 1, 2, 3, 2, 1, 1, 1, 3

Offset: 1

Author

Zhandos Mambetaliyev, Nov 24 2016

Keywords

• nonn

Comments

a(n) <= 5, since A009003 contains all multiples of 5. - Robert Israel, Dec 08 2016

Links

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

Crossrefs

Cf. A009003.

Programs

Maple

L:= select(t -> has(numtheory:-factorset(t) mod 4,1), [$1..1000]):
L[2..-1]-L[1..-2]; # Robert Israel, Dec 08 2016

Mathematica

Differences@ Select[Range@ 208, Length@ PowersRepresentations[#^2, 2, 2] > 1 &] (* Michael De Vlieger, Nov 25 2016, after Alonso del Arte at A009003 *)

Formula

a(n) = A009003(n+1) - A009003(n).