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