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A254655
Run lengths of A254379 (Characteristic function of the even odious numbers).
4
2, 1, 1, 1, 3, 1, 5, 1, 1, 1, 5, 1, 3, 1, 1, 1, 3, 1, 5, 1, 3, 1, 1, 1, 5, 1, 1, 1, 3, 1, 5, 1, 1, 1, 5, 1, 3, 1, 1, 1, 5, 1, 1, 1, 3, 1, 5, 1, 3, 1, 1, 1, 3, 1, 5, 1, 1, 1, 5, 1, 3, 1, 1, 1, 3, 1, 5, 1, 3, 1, 1, 1, 5, 1, 1, 1, 3, 1, 5, 1, 3, 1, 1, 1, 3, 1, 5, 1, 1, 1, 5, 1, 3, 1, 1, 1, 5, 1, 1, 1, 3, 1, 5, 1, 1
OFFSET
1,1
COMMENTS
Also run lengths of A254651 (complement of A254379).
LINKS
EXAMPLE
A254379 begins 0,0,1,0,1,0,0,0,1, hence this sequence begins 2,1,1,1,3,1.
MATHEMATICA
Length /@ Split[Table[If[EvenQ[n] && OddQ[DigitCount[n, 2, 1]], 1, 0], {n, 0, 200}]] (* Amiram Eldar, Aug 07 2023 *)
PROG
(PARI)
up_to = 65537;
A254655lista(up_to) = { my(v=vector(up_to), r=0, n=0, i=0, pb=(hammingweight(i)%2)*!(i%2), b); while(n<up_to, b = (hammingweight(i)%2)*!(i%2); if(b==pb, r++, n++; v[n] = r; r = 1; pb = b); i++); (v); }; \\ Antti Karttunen, Oct 01 2018
v254655 = A254655lista(up_to);
A254655(n) = v254655[n]; \\ Antti Karttunen, Oct 01 2018
(Python)
from itertools import count, islice, groupby
def A254655_gen(): # generator of terms
return (len(list(g)) for k, g in groupby((n&1^1)&n.bit_count() for n in count(0)))
A254655_list = list(islice(A254655_gen(), 20)) # Chai Wah Wu, Mar 09 2023
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Jeremy Gardiner, Feb 04 2015
EXTENSIONS
More terms from Antti Karttunen, Oct 01 2018
STATUS
approved