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Search: id:A113762
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| A113762 |
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Numbers n with nonzero digits in their decimal representation such that when all numbers formed by inserting the exponentiation symbol between any two digits are added up, the sum is prime. |
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+0
2
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| 21, 31, 51, 71, 121, 142, 161, 162, 164, 181, 211, 237, 326, 343, 412, 416, 456, 491, 494, 612, 616, 726, 817, 929, 1226, 1228, 1427, 1513, 1622, 1776, 1824, 1828, 1911, 1915, 1975, 2127, 2188, 3716, 5265, 6276, 6321, 6491, 6852, 7739, 14423, 14487
(list; graph; listen)
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OFFSET
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1,1
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EXAMPLE
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a(6) = 142 because 1^42+14^2 = 197, which is prime.
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MATHEMATICA
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lst = {}; Do[ If[ Min@ IntegerDigits@n > 0, a=0; p=10; While[(w = Floor[n/p]) > 0, a += w^ Mod[n, p]; p*=10]; If[PrimeQ[a], Print[{n, a}]; AppendTo[lst, n]]], {n, 11, 9999}]; lst
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CROSSREFS
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Cf. A117388.
Adjacent sequences: A113759 A113760 A113761 this_sequence A113763 A113764 A113765
Sequence in context: A034101 A034111 A077687 this_sequence A032585 A138822 A104297
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KEYWORD
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base,nonn
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AUTHOR
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Ray Opao (1260(AT)email.com), Jan 18 2006
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EXTENSIONS
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More terms from Giovanni Resta (g.resta(AT)iit.cnr.it), Jan 19 2006
More terms from Robert G. Wilson v (rgwv(at)rgwv.com), Apr 27 2006
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