This site is supported by donations to The OEIS Foundation.



Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing.
Other ways to donate

(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A264986 Even bisection of A263272; terms of A264974 doubled. 4


%S 0,2,4,6,8,10,12,14,32,18,20,38,24,26,28,30,16,34,36,22,40,42,68,86,

%T 96,50,104,54,56,110,60,74,92,114,44,98,72,62,116,78,80,82,84,46,100,

%U 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

%N Even bisection of A263272; terms of A264974 doubled.

%F a(n) = A263272(2*n).

%F a(n) = 2 * A264974(n).

%F a(n) = A263273(4*n)/2.

%o (Scheme) (define (A264986 n) (A263272 (+ n n)))

%o (Python)

%o from sympy import factorint

%o from sympy.ntheory.factor_ import digits

%o from operator import mul

%o def a030102(n): return 0 if n==0 else int(''.join(map(str, digits(n, 3)[1:][::-1])), 3)

%o def a038502(n):

%o f=factorint(n)

%o return 1 if n==1 else reduce(mul, [1 if i==3 else i**f[i] for i in f])

%o def a038500(n): return n/a038502(n)

%o def a263273(n): return 0 if n==0 else a030102(a038502(n))*a038500(n)

%o def a(n): return a263273(4*n)/2 # _Indranil Ghosh_, May 23 2017

%Y Cf. A263272, A264974, A264987.

%K nonn

%O 0,2

%A _Antti Karttunen_, Dec 05 2015

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 12 20:12 EST 2019. Contains 329961 sequences. (Running on oeis4.)