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A292384 a(1) = 1; for n > 1, a(n) = 4*a(A252463(n)) + (n mod 4). 7
1, 6, 27, 24, 109, 110, 439, 96, 97, 438, 1759, 440, 7037, 1758, 443, 384, 28149, 390, 112599, 1752, 1753, 7038, 450399, 1760, 389, 28150, 387, 7032, 1801597, 1774, 7206391, 1536, 7033, 112598, 1775, 1560, 28825565, 450398, 28155, 7008, 115302261, 7014, 461209047, 28152, 1761, 1801598, 1844836191, 7040, 1557, 1558, 112603, 112600 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

a(n) encodes in its base-4 representation the succession of modulo 4 residues obtained when map x -> A252463(x), starting from x=n, is iterated down to the eventual 1.

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..1024

FORMULA

a(1) = 1; for n > 1, a(n) = 4*a(A252463(n)) + A010873(n).

PROG

(Scheme, with memoization-macro definec)

(definec (A292384 n) (if (= 1 n) n (+ (modulo n 4) (* 4 (A292384 (A252463 n))))))

(Python)

from sympy.core.cache import cacheit

from sympy import factorint, prevprime, prod

def a064989(n):

    f = factorint(n)

    return 1 if n == 1 else prod(prevprime(i)**f[i] for i in f if i != 2)

def a252463(n): return 1 if n==1 else n//2 if n%2==0 else a064989(n)

@cacheit

def a(n): return 1 if n==1 else 4*a(a252463(n)) + n%4

print([a(n) for n in range(1, 51)]) # Indranil Ghosh, Sep 21 2017

CROSSREFS

Cf. A010873, A252463, A292380, A292381, A292382, A292383.

Cf. also A292243.

Sequence in context: A137088 A179162 A285806 * A183603 A067876 A309337

Adjacent sequences:  A292381 A292382 A292383 * A292385 A292386 A292387

KEYWORD

nonn,base

AUTHOR

Antti Karttunen, Sep 15 2017

STATUS

approved

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Last modified June 18 16:38 EDT 2021. Contains 345120 sequences. (Running on oeis4.)