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A113338
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Positive integers of the form (18*m^2+1)/11.
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6
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41, 59, 419, 473, 1193, 1283, 2363, 2489, 3929, 4091, 5891, 6089, 8249, 8483, 11003, 11273, 14153, 14459, 17699, 18041, 21641, 22019, 25979, 26393, 30713, 31163, 35843, 36329, 41369, 41891, 47291, 47849, 53609, 54203, 60323, 60953
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| Here m=(11*(2*n-1)-9*(-1)^n)/4 for n>0.
(18*m^2 + 1)/11 is integer for m=5+11k and m=6+11k, k=0,1,2,.... [ Corrected by Bruno Berselli (berselli.bruno(AT)yahoo.it), Jun 28 2010]
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LINKS
| B. Berselli, Table of n, a(n) for n = 1..10000.
Index to sequences with linear recurrences with constant coefficients, signature (1,2,-2,-1,1).
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FORMULA
| Contribution from Bruno Berselli (berselli.bruno(AT)yahoo.it), Jun 29 2010: (Start)
G.f.: x*(41+18*x+278*x^2+18*x^3+41*x^4)/((1+x)^2*(1-x)^3).
a(n) = a(-n+1) = a(n-1)+2*a(n-2)-2*a(n-3)-a(n-4)+a(n-5).
a(n) = (198*n*(n-1)-81*(2*n-1)*(-1)^n+83)/4. (End)
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CROSSREFS
| Cf. A179088, A179337, A179338, A179339, A179370.
Sequence in context: A161613 A139890 A082932 * A116322 A153681 A179826
Adjacent sequences: A113335 A113336 A113337 * A113339 A113340 A113341
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KEYWORD
| nonn,easy
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AUTHOR
| Zak Seidov (zakseidov(AT)yahoo.com), Jan 08 2006
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EXTENSIONS
| Definition corrected, comment and cross-reference added by Bruno Berselli (berselli.bruno(AT)yahoo.it), Jul 13 2010
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