A307784 a(n) is the square root of A034175(n) + A034175(n+1).

1, 2, 3, 4, 5, 6, 5, 3, 4, 5, 4, 3, 4, 5, 6, 7, 8, 9, 8, 7, 8, 9, 10, 8, 5, 6, 7, 8, 9, 10, 9, 7, 8, 9, 8, 7, 8, 9, 10, 8, 5, 6, 7, 8, 9, 10, 9, 8, 9, 10, 11, 12, 13, 14, 13, 12, 11, 9, 10, 11, 12, 13, 12, 11, 12, 13, 14, 15, 14, 12, 13, 14, 13, 12, 11, 12, 14

Offset: 0

Author

Rémy Sigrist, Apr 28 2019

Keywords

• nonn

Comments

The sum of two consecutive terms of A034175 is always a perfect square.

Examples

			For n = 12:
- A034175(12) + A034175(13) = 7 + 9 = 16 = 4^2,
- hence a(12) = 4.
		

Links

• Rémy Sigrist, Table of n, a(n) for n = 0..10000

Crossrefs

Cf. A034175.

Programs

PARI

p=0; s=0; for (n=1, 77, s+=2^p; for (v=0, oo, if (!bittest(s,v) && issquare(p+v), print1 (sqrtint(p+v) ", "); p=v; break)))

Formula

a(n)^2 = A034175(n) + A034175(n+1).