OFFSET
0,7
COMMENTS
The positions of the zeros seem to be given by A000975.
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000
MATHEMATICA
A048702 := Join[{0}, Reap[For[k = 1, k < 1500, k += 2, bb = IntegerDigits[k, 2]; If[bb == Reverse[bb], If[EvenQ[Length[bb]], Sow[k/3]]]]][[2, 1]]]; Table[n*(n + 1)/2 - A048702[[n + 1]], {n, 0, 50}] (* G. C. Greubel, Sep 26 2017 *)
PROG
(PARI) a01(n) = my(f); f = length(binary(n)) - 1; 2^(f+1)*n + sum(i=0, f, bittest(n, i) * 2^(f-i)); \\ A048701
a(n) = n*(n+1)/2 - a01(n)/3; \\ A006095
(Python)
def A075113(n: int) -> int:
s = bin(n)[2:]
return n * (n + 1) // 2 - int(s + s[::-1], 2) // 3
print([A075113(n) for n in range(69)]) # Peter Luschny, Dec 14 2022
CROSSREFS
KEYWORD
sign
AUTHOR
Antti Karttunen, Sep 02 2002
EXTENSIONS
Definition corrected by Georg Fischer, Dec 13 2022
STATUS
approved