The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A292372 A binary encoding of 2-digits in base-4 representation of n. 6
 0, 0, 1, 0, 0, 0, 1, 0, 2, 2, 3, 2, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 2, 2, 3, 2, 0, 0, 1, 0, 4, 4, 5, 4, 4, 4, 5, 4, 6, 6, 7, 6, 4, 4, 5, 4, 0, 0, 1, 0, 0, 0, 1, 0, 2, 2, 3, 2, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 2, 2, 3, 2, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 2, 2, 3, 2, 0, 0, 1, 0, 4, 4, 5, 4, 4, 4, 5, 4, 6, 6, 7, 6, 4, 4, 5, 4, 0, 0, 1, 0, 0, 0, 1, 0, 2 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,9 LINKS Antti Karttunen, Table of n, a(n) for n = 0..65536 FORMULA a(n) = A059906(n AND A048724(n)), where AND is a bitwise-AND (A004198). For all n >= 0, A000120(a(n)) = A160382(n). EXAMPLE n      a(n)     base-4(n)  binary(a(n))                   A007090(n)  A007088(a(n))   --      ----    ----------  ------------    1        0          1           0    2        1          2           1    3        0          3           0    4        0         10           0    5        0         11           0    6        1         12           1    7        0         13           0    8        2         20          10    9        2         21          10   10        3         22          11   11        2         23          10   12        0         30           0   13        0         31           0   14        1         32           1   15        0         33           0   16        0        100           0   17        0        101           0   18        1        102           1 MATHEMATICA Table[FromDigits[IntegerDigits[n, 4] /. k_ /; IntegerQ@ k :> If[k == 2, 1, 0], 2], {n, 0, 120}] (* Michael De Vlieger, Sep 21 2017 *) PROG (Scheme, with memoization-macro definec) (definec (A292372 n) (if (zero? n) n (let ((d (modulo n 4))) (+ (if (= 2 d) 1 0) (* 2 (A292372 (/ (- n d) 4))))))) (Python) from sympy.ntheory.factor_ import digits def a(n):     k=digits(n, 4)[1:]     return 0 if n==0 else int("".join('1' if i==2 else '0' for i in k), 2) print([a(n) for n in range(121)]) # Indranil Ghosh, Sep 21 2017 CROSSREFS Cf. A004198, A007088, A007090, A048724, A059906, A160382, A292370, A292371, A292373. Cf. A289814 (analogous sequence for base-3). Sequence in context: A022461 A306821 A271226 * A098008 A234808 A248079 Adjacent sequences:  A292369 A292370 A292371 * A292373 A292374 A292375 KEYWORD nonn,base AUTHOR Antti Karttunen, Sep 15 2017 STATUS approved

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.

Last modified July 28 17:15 EDT 2021. Contains 346335 sequences. (Running on oeis4.)