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Search: id:A061579
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| A061579 |
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Reverse one number (0), then two numbers (2,1), then three (5,4,3), then four (9,8,7,6), etc. |
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+0
12
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| 0, 2, 1, 5, 4, 3, 9, 8, 7, 6, 14, 13, 12, 11, 10, 20, 19, 18, 17, 16, 15, 27, 26, 25, 24, 23, 22, 21, 35, 34, 33, 32, 31, 30, 29, 28, 44, 43, 42, 41, 40, 39, 38, 37, 36, 54, 53, 52, 51, 50, 49, 48, 47, 46, 45, 65, 64, 63, 62, 61, 60, 59, 58, 57, 56, 55, 77, 76, 75, 74, 73, 72
(list; table; graph; listen)
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OFFSET
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0,2
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COMMENT
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a(n) is the smallest non-negative integer not yet in the sequence such that n + a(n) is one less than a square. [From Franklin T. Adams-Watters (FrankTAW(AT)Netscape.net), Apr 06 2009]
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LINKS
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Harry J. Smith, Table of n, a(n) for n=0,...,1000
Index entries for sequences that are permutations of the natural numbers
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FORMULA
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a(n) =[sqrt(2n+1)-1/2]*[sqrt(2n+1)+3/2]-n =A005563(A003056(n))-n
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PROGRAM
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(PARI) { default(realprecision, 100); for (n=0, 1000, f=floor(sqrt(2*n + 1) - 1/2); write("b061579.txt", n, " ", f*(f + 2) - n) ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Jul 25 2009]
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CROSSREFS
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Fixed points are A046092. Each reversal involves the numbers from A000217 through to A000096.
A self-inverse permutation of the nonnegative numbers.
Cf. A038722. Transpose of A001477.
Sequence in context: A113350 A164678 A164679 this_sequence A094064 A159930 A058344
Adjacent sequences: A061576 A061577 A061578 this_sequence A061580 A061581 A061582
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KEYWORD
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nonn,tabl
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AUTHOR
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Henry Bottomley (se16(AT)btinternet.com), May 21 2001
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