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Search: id:A036353
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| A036353 |
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Square pentagonal numbers. |
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+0
4
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| 0, 1, 9801, 94109401, 903638458801, 8676736387298001, 83314021887196947001, 799981229484128697805801, 7681419682192581869134354401, 73756990988431941623299373152801
(list; graph; listen)
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OFFSET
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0,3
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LINKS
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Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics.
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FORMULA
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a(n) = 9602*a(n-1) - a(n-2) + 200; g.f.: (1+198*x+x^2)/((1-x)*(1-9602*x+x^2)) - Warut Roonguthai (warut822(AT)yahoo.com) Jan 05 2001
a(n+1)=4801*a(n)+100+980*(24*a(n)^2+a(n))^0.5. G.f.: h(z)=(z*(1+198*z+z^2))/((1-z)*(1-960*z+z^2)) - Richard Choulet (richardchoulet(AT)yahoo.fr), Sep 19 2007
a(n+1)=4801*a(n)+100+980*(24*a(n)^2+a(n))^0.5 - Richard Choulet (richardchoulet(AT)yahoo.fr), Sep 21 2007
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PROGRAM
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(PARI) for(n=0, 10^9, g=(n*(3*n-1)/2); if(issquare(g), print(g)))
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CROSSREFS
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Cf. A046172, A046173, A000326, A001110.
Cf. A001079 A046173 A046172 A001078.
Cf. A046172 A046173 A001079.
Sequence in context: A035911 A069333 A113937 this_sequence A031687 A031597 A031777
Adjacent sequences: A036350 A036351 A036352 this_sequence A036354 A036355 A036356
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KEYWORD
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nonn,easy
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AUTHOR
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Jean-Francois Chariot (jeanfrancois.chariot(AT)afoc.alcatel.fr)
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EXTENSIONS
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More terms from Eric Weisstein (eric(AT)weisstein.com)
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