

A101625


A bisection of the SternJacobsthal numbers.


5



0, 1, 1, 5, 1, 21, 17, 69, 1, 277, 273, 1349, 257, 5141, 4113, 16453, 1, 65813, 65809, 329029, 65793, 1381397, 1118225, 4538437, 65537, 18088213, 17826065, 88081733, 16777473, 335549461, 268439569, 1073758277, 1, 4295033109, 4295033105
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OFFSET

0,4


LINKS

Ivan Panchenko, Table of n, a(n) for n = 0..1000


FORMULA

a(n) = Sum_{k=0..n} (binomial(2nk, k1) mod 2)2^(k1);
a(n) = A101624(2n+1).
a(0)=0, a(1)=1, a(n) = a(n1) XOR (a(n2)*4), where XOR is the bitwise exclusiveOR operator.  Alex Ratushnyak, May 06 2012
a(n+1) = Sum_{k=0..n} A106344(n,k)*4^(nk).  Philippe Deléham, May 27 2012


PROG

(Python)
prpr = 0
prev = 1
for i in range(99):
current = (prev)^(prpr*4)
print(prpr, end=', ')
prpr = prev
prev = current
# Alex Ratushnyak, May 06 2012


CROSSREFS

Cf. A002450.
Sequence in context: A095368 A029757 A146056 * A051929 A347487 A213118
Adjacent sequences: A101622 A101623 A101624 * A101626 A101627 A101628


KEYWORD

easy,nonn


AUTHOR

Paul Barry, Dec 10 2004


STATUS

approved



