A292384 a(1) = 1; for n > 1, a(n) = 4*a(A252463(n)) + (n mod 4).

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

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: A356813 A179162 A285806 * A183603 A067876 A309337

Adjacent sequences: A292381 A292382 A292383 * A292385 A292386 A292387

Keyword

nonn,base

Author

Antti Karttunen, Sep 15 2017

Status

approved