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A037095
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"Sloping binary representation" of powers of 3 (A000244), slope = -1.
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5
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1, 1, 3, 1, 3, 9, 11, 17, 19, 25, 123, 65, 195, 169, 171, 753, 435, 249, 2267, 4065, 8163, 841, 843, 31313, 29651
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,3
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FORMULA
| a(n) := Sum(bit_n(A000244(n-i), i)*(2^i), i=0..(n-1)) [ bit_n := (x, n) -> `mod`(floor(x/(2^n)), 2); ]
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EXAMPLE
| When powers of 3 are written in binary (see A004656), under each other as:
000000000001 (1)
000000000011 (3)
000000001001 (9)
000000011011 (27)
000001010001 (81)
000011110011 (243)
001011011001 (729)
100010001011 (2187)
and one collects their bits from the column-0 to NW-direction (from the least to the most significant end), one gets 1 (1), 01 (1), 011 (3), 0001 (1), 00011 (3), 001001 (9), etc. (See A105033 for similar transformation done on nonnegative integers).
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CROSSREFS
| Cf. A105033, A000244, A037093-A037094, A037096-A037097.
Sequence in context: A164308 A082511 A088442 * A160654 A146436 A058842
Adjacent sequences: A037092 A037093 A037094 * A037096 A037097 A037098
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KEYWORD
| nonn,base
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AUTHOR
| Antti Karttunen (His_Firstname.His_Surname(AT)gmail.com), Jan 28 1999. Entry revised Dec 29 2007.
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