A104806 "Round of hypotenuse", see comments.

1, 3, 3, 4, 5, 7, 9, 11, 14, 18, 23, 29, 37, 47, 60, 77, 97, 124, 158, 201, 255, 324, 413, 525, 668, 849, 1081, 1374, 1748, 2224, 2829, 3598, 4577, 5822, 7406, 9421, 11983, 15243, 19389, 24664, 31373, 39907, 50762, 64571, 82135, 104477, 132897, 169048, 215032, 273526

Offset

1,2

Comments

Start with a=1, b=3; repeating procedure "c=sqrt(a^2+b^2), a=b, b=c" gives: s = 1, 3, sqrt(10), sqrt(19), sqrt(29), 4*sqrt(3), sqrt(77), 5*sqrt(5), sqrt(202), sqrt(327), 23, 2*sqrt(214), sqrt(1385), 3*sqrt(249),... Then a(n) = round(s(n)).

Links

Table of n, a(n) for n=1..50.

Formula

a(n) = A000194(A022099(n-1)). - Jason Yuen, Mar 07 2026

Crossrefs

Cf. A000194, A022099, A104803, A104804, A104805.

Sequence in context: A239640 A100091 A239483 * A241442 A378750 A363091

Adjacent sequences: A104803 A104804 A104805 * A104807 A104808 A104809

Keyword

nonn,easy

Author

Zak Seidov, Mar 26 2005

Extensions

More terms from Jason Yuen, Mar 07 2026

Status

approved