A092960 Least square of the form 'sum of n successive terms of a geometric progression + 1', or 0 if no such square exists.

1, 4, 36, 16, 900, 64, 15876, 256, 47524, 1024, 386884, 4096, 67076100, 16384, 21921124, 65536, 17179344900, 262144, 274875809796, 1048576, 148371336100, 4194304, 9206236135684, 16777216, 1167694198801, 67108864, 367640742081600, 268435456, 3836162239297600

Offset

1,2

Comments

Conjecture: No term is zero.

If n is even, a(n) = 2^n. - Ray G. Opao, Feb 25 2005

Links

Table of n, a(n) for n=1..29.

Example

a(3) = 36 = (5 + 10 + 20) + 1. a(4) = 16 = (1 + 2 + 4 + 8) + 1.

Crossrefs

Cf. A092959.

Sequence in context: A174413 A162990 A366729 * A323515 A374371 A144153

Adjacent sequences: A092957 A092958 A092959 * A092961 A092962 A092963

Keyword

nonn

Author

Amarnath Murthy, Mar 25 2004

Extensions

Corrected and extended by Ray G. Opao, Feb 25 2005

a(11)-a(27) from Donovan Johnson, May 20 2010

a(28)-a(29) from Donovan Johnson, Sep 20 2012

Status

approved