A180273 Squares which are a sum of consecutive squares starting with 7^2.

49, 8464, 20449, 60025, 2304324, 3624882849

Offset

1,1

Comments

That is, terms are squares of the form sum_{i=7..m} i^2 for some m. This sequence is complete. See A180442 and A184763.

Links

Table of n, a(n) for n=1..6.

Example

a(2) = 8464 = 92^2 = 7^2+8^2+9^2+...+28^2+29^2.

Mathematica

Select[Accumulate[Range[7, 3000]^2], IntegerQ[Sqrt[#]]&] (* Harvey P. Dale, Jul 16 2014 *)

Prog

(PARI) for(n=8, 9999999, t=n*(n+1)*(2*n+1)/6-91; if(issquare(t), print1(t, ", ")))

Crossrefs

Cf. A001032, A094196, A151557, A180259.

Sequence in context: A304313 A283788 A206247 * A351598 A014801 A187406

Adjacent sequences: A180270 A180271 A180272 * A180274 A180275 A180276

Keyword

nonn,easy,fini,full

Author

Zhining Yang, Jan 17 2011

Status

approved