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A264986
Even bisection of A263272; terms of A264974 doubled.
4
0, 2, 4, 6, 8, 10, 12, 14, 32, 18, 20, 38, 24, 26, 28, 30, 16, 34, 36, 22, 40, 42, 68, 86, 96, 50, 104, 54, 56, 110, 60, 74, 92, 114, 44, 98, 72, 62, 116, 78, 80, 82, 84, 46, 100, 90, 64, 118, 48, 70, 88, 102, 52, 106, 108, 58, 112, 66, 76, 94, 120, 122, 284, 126, 176, 338, 204, 230, 248, 258, 140, 302, 288
OFFSET
0,2
FORMULA
a(n) = A263272(2*n).
a(n) = 2 * A264974(n).
a(n) = A263273(4*n)/2.
PROG
(Scheme) (define (A264986 n) (A263272 (+ n n)))
(Python)
from sympy import factorint
from sympy.ntheory.factor_ import digits
from operator import mul
def a030102(n): return 0 if n==0 else int(''.join(map(str, digits(n, 3)[1:][::-1])), 3)
def a038502(n):
f=factorint(n)
return 1 if n==1 else reduce(mul, [1 if i==3 else i**f[i] for i in f])
def a038500(n): return n/a038502(n)
def a263273(n): return 0 if n==0 else a030102(a038502(n))*a038500(n)
def a(n): return a263273(4*n)/2 # Indranil Ghosh, May 23 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Dec 05 2015
STATUS
approved