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A264980 Base-3 reversal of 2^n: a(n) = A030102(A000079(n)). 5
1, 2, 4, 8, 16, 64, 32, 184, 352, 704, 1408, 1880, 2824, 14032, 10328, 56128, 100576, 145784, 189472, 370304, 731752, 4388248, 2924096, 11175712, 15965704, 31930448, 63861880, 383165344, 255439712, 1021772344, 510875648, 2550188248, 5619691648, 9689861048, 17830350904, 79068724264, 34109913224, 192259976368, 133338241880 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
LINKS
FORMULA
a(n) = A030102(A000079(n)) = A263273(A000079(n)).
a(0) = 1, for n >= 1, a(n) = A265342(a(n-1)).
EXAMPLE
2^5 = 32 in base 3 = "1012" (= A007089(32)) as 1*27 + 1*3 + 2*1 = 32. 2^6 = 64 in base 3 = "2101" as 2*27 + 1*9 + 1*1 = 64. "1012" reversed is "2101" and vice versa, thus a(5) = 64 and a(6) = 32.
PROG
(Scheme, two alternatives)
(define (A264980 n) (A030102 (A000079 n)))
(define (A264980 n) (if (zero? n) 1 (A265342 (A264980 (- n 1)))))
(PARI) base(n) = {my(a=[n%3]); while(0<n\=3, a=concat(n%3, a)); a}
a(n) = subst(Polrev(base(2^n)), x, 3); \\ Altug Alkan, Dec 29 2015
CROSSREFS
Leftmost column of A265345.
Cf. also A036215.
Sequence in context: A018735 A041013 A018754 * A318151 A076086 A246907
KEYWORD
nonn,base
AUTHOR
Antti Karttunen, Dec 05 2015
STATUS
approved

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Last modified May 23 11:57 EDT 2024. Contains 372763 sequences. (Running on oeis4.)