A061886 Largest square less than or equal to sum of previous terms.

1, 1, 1, 1, 4, 4, 9, 16, 36, 64, 121, 256, 484, 961, 1936, 3844, 7569, 15129, 30276, 60516, 121104, 242064, 483025, 966289, 1932100, 3865156, 7728400, 15452761, 30902481, 61811044, 123609924, 247212729, 494439696, 988850916, 1977669841

Offset

0,5

Links

Reinhard Zumkeller, Table of n, a(n) for n = 0..1000

Formula

For n > 0: a(n) = A060984(n+1)-A060984(n) = A048760(A060984(n)).

Example

a(6) = 9 since 1+1+1+1+4+4 = 12 and 9 is the largest square less than or equal to this.

Prog

(Haskell)
a061886 n = a061886_list !! n
a061886_list = 1 : zipWith (-) (tail a060984_list) a060984_list
-- Reinhard Zumkeller, Dec 24 2013

Crossrefs

Cf. A061883.

Sequence in context: A304990 A263727 A133037 * A059815 A202670 A203003

Adjacent sequences: A061883 A061884 A061885 * A061887 A061888 A061889

Keyword

nonn

Author

Henry Bottomley, May 12 2001

Extensions

Formula corrected by Reinhard Zumkeller, Dec 24 2013

Status

approved