A180347 The number of n-digit numbers requiring 4 nonzero squares in their representation as sum of squares.

1, 14, 150, 1500, 14999, 150000, 1499999, 15000000, 149999998, 1500000001, 14999999999, 149999999999, 1500000000001, 14999999999999, 149999999999999, 1500000000000001, 14999999999999998, 149999999999999999, 1500000000000000003, 14999999999999999996

Offset

1,2

Comments

A049415(n) + A180426(n) + A180429(n) + a(n) = A052268(n).

Links

Table of n, a(n) for n=1..20.

Eric W. Weisstein: MathWorld : Lagrange's Four-Square Theorem.

Eric W. Weisstein: MathWorld: Sum of Squares Function.

Formula

a(n) = A167615(n)-A167615(n-1).

Crossrefs

Cf. A004215, A167615.

Cf. A049415, A052268, A180426, A180429.

Sequence in context: A009614 A009802 A153598 * A262183 A357484 A037960

Adjacent sequences: A180344 A180345 A180346 * A180348 A180349 A180350

Keyword

nonn,base

Author

Martin Renner, Jan 18 2011

Status

approved