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1, 8, 50, 344, 2402, 16808, 117650, 823544, 5764802, 40353608, 282475250, 1977326744, 13841287202, 96889010408, 678223072850, 4747561509944, 33232930569602, 232630513987208, 1628413597910450, 11398895185373144
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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COMMENTS
| a(n)^3 is palindromic in base 7 (1,1331,1030301,1003003001,....)
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LINKS
| P. De Geest, World!Of Numbers
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FORMULA
| G.f.: (1-7x^2)/((1-x)(1-7x)); a(n)=sum{k=0..n, binomial(n, k)*0^(k(n-k))*7^k}.
a(n)=A034491(n), n>0. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Aug 28 2008]
a(n)=7*a(n-1)-6, with a(1)=8. [From Vincenzo Librandi, Dec 29 2010]
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CROSSREFS
| Cf. A046233.
Sequence in context: A061801 A180029 A133129 * A100310 A124963 A195231
Adjacent sequences: A103455 A103456 A103457 * A103459 A103460 A103461
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KEYWORD
| easy,nonn
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AUTHOR
| Paul Barry (pbarry(AT)wit.ie), Feb 07 2005
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