OFFSET
0,1
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 0..1000
FORMULA
a(n) = 12*A089893(n) + 3.
a(n+1) = (2 * a(n)) XOR (3 * a(n)), where XOR is the bitwise exclusive or operator. - Federico Provvedi, Sep 14 2023
MATHEMATICA
NestList[BitXor[2#, 3#]&, 3, 30] (* Federico Provvedi, Sep 14 2023 *)
PROG
(PARI) a(n)=sum(k=0, 2*n+1, (binomial(2*n+1, k)%2)<<k) \\ Charles R Greathouse IV, Aug 08 2013
(PARI) A011371(n)=my(s); while(n>>=1, s+=n); s
a(n)=n+=n+1; sum(k=0, n, A047999(n, k)<<k) \\ Charles R Greathouse IV, Aug 09 2013
(Python)
def A038192(n): return sum((bool(~(m:=(n<<1)+1)&m-k)^1)<<k for k in range((n+1)<<1)) # Chai Wah Wu, May 02 2023
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved