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Search: id:A153498
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| A153498 |
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Palindromes formed from concatenation of A147759(n) and the same string A147759(n) but without its initial digit. |
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+0
4
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| 1, 111, 10101, 1001001, 101010101, 10110101101, 1010101010101, 101001010100101, 10101010101010101, 1010110101010110101, 101010101010101010101, 10101001010101010010101
(list; graph; listen)
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OFFSET
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1,2
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COMMENT
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a(n) is also A153497(n) written in base 2.
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FORMULA
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a(n)=101*a(n-1)-1110*a(n-2)+102010*a(n-3)-111000*a(n-4)+1010000*a(n-5)-1000000*a(n-6). G.f.: x(1+10x+2000x^3-91000*x^4+100000x^5)/((1-100x)(1-x)(1+10x^2)(1+1000x^2)). [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Feb 20 2009]
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EXAMPLE
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n ............. a(n)
1 .............. 1
2 ............. 111
3 ............ 10101
4 ........... 1001001
5 .......... 101010101
6 ......... 10110101101
7 ........ 1010101010101
8 ....... 101001010100101
9 ...... 10101010101010101
10 .... 1010110101010110101
11 ... 101010101010101010101
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CROSSREFS
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Cf. A135577, A138146, A152576, A152764, A153497, A153499, A153500, A144564.
Sequence in context: A129051 A012039 A135577 this_sequence A152764 A138146 A100706
Adjacent sequences: A153495 A153496 A153497 this_sequence A153499 A153500 A153501
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KEYWORD
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easy,more,nonn
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AUTHOR
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Omar E. Pol (info(AT)polprimos.com), Dec 27 2008, Feb 18 2009
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EXTENSIONS
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More terms from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Feb 20 2009
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