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Search: id:A046191
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| A046191 |
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Indices of hexagonal numbers which are also octagonal. |
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+0
3
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| 1, 77, 7521, 736957, 72214241, 7076258637, 693401132161, 67946234693117, 6658037598793281, 652419738447048397, 63930476330211949601, 6264534260622324012477, 613860427064657541273121
(list; graph; listen)
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OFFSET
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1,2
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LINKS
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Herman Jamke (hermanjamke(AT)fastmail.fm), Apr 19 2008, Table of n, a(n) for n = 1..20
Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics.
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MAPLE
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a:=5+2*sqrt(6): b:=5-2*sqrt(6): s:=n->a^n+b^n: d:=n->sqrt(6)*(a^n-b^n):for n from 0 to 40 do x:=simplify(s(n)-1/4*d(n)): y:=simplify(1/3*d(n)-s(n)/2): if(type((1+x/2)/3, integer) and type((1+y)/4, integer)) then printf("%d, ", (1+y)/4) fi: x:=simplify(s(n+1)+1/4*d(n+1)): y:=simplify(1/3*d(n+1)+s(n+1)/2): if(type((1+x/2)/3, integer) and type((1+y)/4, integer)) then printf("%d, ", (1+y)/4) fi: od: - Herman Jamke (hermanjamke(AT)fastmail.fm), Apr 19 2008
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CROSSREFS
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Cf. A046190, A046192.
Adjacent sequences: A046188 A046189 A046190 this_sequence A046192 A046193 A046194
Sequence in context: A116319 A107787 A099638 this_sequence A115616 A120799 A098024
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KEYWORD
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nonn
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AUTHOR
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Eric Weisstein (eric(AT)weisstein.com)
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EXTENSIONS
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1 more term from Larry Reeves (larryr(AT)acm.org), May 07 2001
One more term from Lior Manor (lior.manor(AT)gmail.com) Feb 13 2002
More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Apr 19 2008
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