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A293170
Number of distinct subsequences of the binary expansion of n.
2
2, 2, 4, 3, 6, 7, 6, 4, 8, 11, 12, 10, 9, 10, 8, 5, 10, 15, 18, 16, 17, 20, 18, 13, 12, 16, 17, 14, 12, 13, 10, 6, 12, 19, 24, 22, 25, 30, 28, 21, 22, 30, 33, 28, 26, 29, 24, 16, 15, 22, 26, 23, 24, 28, 25, 18, 16, 21, 22, 18, 15, 16, 12, 7, 14, 23, 30, 28, 33, 40, 38
OFFSET
0,1
LINKS
PROG
(PARI) a(n)={if(!n, 2, my(M=Map(Mat([1, 1]))); while(n, my(R=Mat(M)[, 1]); for(i=1, #R, mapput(M, bitor(R[i]<<1, bittest(n, 0)), 1)); n>>=1); #M)} \\ Andrew Howroyd, Mar 01 2020
(PARI) a(n)={if(!n, 2, my(p=vector(2), s=1); while(n, my(k=1+bitand(n, 1), t=s); s = 2*s-p[k]; p[k] = t; n>>=1); s)} \\ Andrew Howroyd, Mar 26 2020
CROSSREFS
a(n) = A293722(n) + 1.
Sequence in context: A357709 A238790 A238787 * A341469 A101200 A122585
KEYWORD
nonn,look,base
AUTHOR
N. J. A. Sloane, Oct 18 2017
EXTENSIONS
Terms a(50) and beyond from Andrew Howroyd, Mar 01 2020
STATUS
approved