A055097 Number of divisors for each term in the triangle A055096. It is 2 for primes (all of the form 4k+1).

2, 4, 2, 2, 6, 3, 4, 2, 4, 2, 2, 8, 6, 6, 2, 6, 2, 4, 4, 4, 4, 4, 6, 2, 10, 2, 9, 2, 4, 4, 12, 2, 4, 6, 8, 4, 2, 8, 2, 6, 4, 8, 2, 6, 2, 4, 4, 8, 2, 4, 2, 8, 4, 4, 4, 4, 6, 6, 12, 3, 18, 2, 10, 9, 6, 4, 8, 2, 4, 4, 4, 4, 4, 2, 8, 2, 8, 2, 2, 12, 4, 6, 4, 8, 6, 12, 2, 8, 2, 12, 4, 4, 2, 12, 2, 8, 6, 4, 3

Offset: 1

Author

Antti Karttunen, Apr 04 2000

Keywords

• nonn
• tabl

Crossrefs

Cf. A055132.

Programs

Maple

sum2distinct_squares_array := (n) -> (((n-((trinv(n-1)*(trinv(n-1)-1))/2))^2)+((trinv(n-1)+1)^2));
with(numtheory, tau); a(n) = tau(sum2distinct_squares_array(n))