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Search: id:A061801
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| 1, 8, 50, 302, 1814, 10886, 65318, 391910, 2351462, 14108774, 84652646, 507915878, 3047495270, 18284971622, 109709829734, 658258978406, 3949553870438, 23697323222630, 142183939335782, 853103636014694
(list; graph; listen)
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OFFSET
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0,2
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COMMENT
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Sum of n-th row of triangle of powers of 6: 1; 1 6 1; 1 6 36 6 1; 1 6 36 216 36 6 1; ....
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LINKS
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Harry J. Smith, Table of n, a(n) for n=0,...,200
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FORMULA
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G.f.:x*(1+x)/(1-6*x)/(1-x) [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Jan 11 2009]
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EXAMPLE
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a(2) = 50 = 1 + 6 + 36 + 6 + 1.
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MAPLE
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restart:g:=x*(1+x)/(1-6*x)/(1-x): gser:=series(g, x=0, 43): seq(coeff(gser, x, n), n=1..30); [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Jan 11 2009]
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PROGRAM
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(PARI) { for (n=0, 200, write("b061801.txt", n, " ", (7*6^n - 2)/5) ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Jul 28 2009]
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CROSSREFS
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Cf. A057651.
Sequence in context: A115598 A127745 A037547 this_sequence A133129 A103458 A100310
Adjacent sequences: A061798 A061799 A061800 this_sequence A061802 A061803 A061804
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KEYWORD
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nonn,easy
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AUTHOR
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Amarnath Murthy (amarnath_murthy(AT)yahoo.com), May 28 2001
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EXTENSIONS
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More terms from Larry Reeves (larryr(AT)acm.org) and Jason Earls (zevi_35711(AT)yahoo.com), May 28 2001. Better description from Dean Hickerson, Jun 06 2001.
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