A180429 The number of n-digit numbers requiring 3 nonzero squares in their representation as sum of squares.

2, 40, 463, 5081, 53722, 557687, 5730883, 58527612, 595228791, 6035604901, 61067111413, 616833883887, 6222429697992, 62704089037652, 631334954674157, 6352077572091621

Offset: 1

Author

Martin Renner, Jan 19 2011

Keywords

• nonn
• more
• base

Comments

A049415(n) + A180426(n) + a(n) + A180347(n) = A052268(n)

Links

• Eric Weisstein's World of Mathematics, Lagrange's Four-Square Theorem, Sum of Squares Function.

Crossrefs

Cf. A000419, A180425.

Formula

a(n) = A180425(n)-A180425(n-1) for n>1.

Extensions

a(6) from Lars Blomberg, Jun 29 2011

a(7)-a(10) from Donovan Johnson, Jul 01 2011

a(10) corrected and a(11)-a(16) added by Hiroaki Yamanouchi, Aug 30 2014