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A139245
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a(n) = 20*n - 16.
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17
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4, 24, 44, 64, 84, 104, 124, 144, 164, 184, 204, 224, 244, 264, 284, 304, 324, 344, 364, 384, 404, 424, 444, 464, 484, 504, 524, 544, 564, 584, 604, 624, 644, 664, 684, 704, 724, 744, 764, 784, 804, 824, 844, 864, 884, 904, 924, 944, 964, 984, 1004, 1024, 1044
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OFFSET
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1,1
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COMMENTS
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Multiples of 4 with the unit digit equal to 4.
Positive integers that are the product of two integers ending with 2 (see A017293). - Stefano Spezia, Jul 25 2021
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LINKS
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FORMULA
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a(n) = a(n-1) + 20.
O.g.f.: 4*x*(1 + 4*x)/(1 - x)^2.
E.g.f.: 16 + 4*exp(x)*(5*x - 4).
a(n) = 2*a(n-1) - a(n-2) for n > 2. (End)
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MAPLE
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MATHEMATICA
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PROG
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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