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Search: id:A110939
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| A110939 |
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Triangular Kaprekar-like numbers: numbers n such that the representation of T(n)=n(n+1)/2 can be separated into two parts xy such that x+y=n. |
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+0
1
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| 9, 10, 18, 19, 45, 55, 99, 100, 144, 154, 198, 199, 297, 703, 999, 1000, 1296, 1702, 1998, 1999, 2223, 2728, 4879, 4950, 5050, 5292, 7272, 7777, 9999, 10000, 12222, 12727, 14949, 15049, 17271, 17344, 17776, 19998, 19999, 22222, 38962, 77778
(list; graph; listen)
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OFFSET
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1,1
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EXAMPLE
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2223 is a member, since the 2223-rd triangular number is 2471976 and 247+1976=2223.
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MAPLE
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lst = {}; Do[t = n(n + 1)/2; p=10; While[t>p, If[Mod[t, p]+Floor[t/p]==n, AppendTo[lst, n]]; p*=10], {n, 200000}]; lst
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CROSSREFS
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Cf. A006886.
Adjacent sequences: A110936 A110937 A110938 this_sequence A110940 A110941 A110942
Sequence in context: A090570 A131417 A058369 this_sequence A015898 A050551 A022099
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KEYWORD
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base,nonn
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AUTHOR
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Giovanni Resta (g.resta(AT)iit.cnr.it), Jan 21 2006
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