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A162742 Reverse digits in the binary representation of each prime base in the prime factorization of n. 2
1, 1, 3, 1, 5, 3, 7, 1, 9, 5, 13, 3, 11, 7, 15, 1, 17, 9, 25, 5, 21, 13, 29, 3, 25, 11, 27, 7, 23, 15, 31, 1, 39, 17, 35, 9, 41, 25, 33, 5, 37, 21, 53, 13, 45, 29, 61, 3, 49, 25, 51, 11, 43, 27, 65, 7, 75, 23, 55, 15, 47, 31, 63, 1, 55, 39, 97, 17, 87, 35, 113, 9, 73, 41, 75, 25, 91, 33 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Base-2 variant of A071786: apply the bit-reversion A030101 to each of the primes in the bases of the prime factorization of n.

LINKS

Alois P. Heinz, Table of n, a(n) for n = 1..20000

FORMULA

A161955(n) = A030101(a(n)).

EXAMPLE

At n=8=2^3, represent 2 as 10 in binary, reverse 10 to give 1, and recombine as 1^3=1 = a(8). At n=14=2*7 =(10)*(111) in binary, reverse the factors to give (1)*(111)=1*7=7=a(14).

MAPLE

A030101 := proc(n) local dgs ; dgs := convert(n, base, 2) ; add( op(-i, dgs)*2^(i-1), i=1..nops(dgs)) ; end:

A162742 := proc(n) local a, p ; a := 1 ; for p in ifactors(n)[2] do a := a* A030101(op(1, p))^op(2, p) ; od: a; end:

CROSSREFS

Sequence in context: A171968 A093474 A030101 * A081432 A318060 A136655

Adjacent sequences:  A162739 A162740 A162741 * A162743 A162744 A162745

KEYWORD

base,easy,nonn,mult

AUTHOR

R. J. Mathar, Jul 12 2009

EXTENSIONS

Cleaned up the definition and corrected the second example - R. J. Mathar, Aug 03 2009

STATUS

approved

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Last modified June 15 16:13 EDT 2019. Contains 324142 sequences. (Running on oeis4.)