A067859 a(1) = 1; a(n+1) = floor(sqrt(Sum_{k=1..n} a(k)^2)).

1, 1, 1, 1, 2, 2, 3, 4, 6, 8, 11, 16, 22, 31, 44, 62, 87, 123, 174, 246, 348, 492, 695, 983, 1390, 1966, 2780, 3931, 5559, 7862, 11118, 15723, 22236, 31446, 44471, 62892, 88942, 125783, 177884, 251566, 355768, 503132, 711536, 1006263, 1423071, 2012526, 2846142

Offset

1,5

Links

Table of n, a(n) for n=1..47.

Example

a(6) = floor(sqrt(1^2 + 1^2 + 1^2 + 1^2 + 2^2)) = floor(sqrt(8)) = 2.

Maple

a:= proc(n) option remember; `if`(n=1, 1,
      floor(sqrt(add(a(k)^2, k=1..n-1))))
    end:
seq(a(n), n=1..60);  # Alois P. Heinz, Aug 03 2018

Crossrefs

Sequence in context: A173508 A103632 A214076 * A006207 A318403 A362048

Adjacent sequences: A067856 A067857 A067858 * A067860 A067861 A067862

Keyword

easy,nonn

Author

Leroy Quet, Feb 15 2002

Status

approved