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A101625 A bisection of the Stern-Jacobsthal 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 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

LINKS

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

FORMULA

a(n) = Sum_{k=0..n} (binomial(2n-k, k-1) mod 2)2^(k-1);

a(n) = A101624(2n+1).

a(0)=0, a(1)=1, a(n) = a(n-1) XOR (a(n-2)*4), where XOR is the bitwise exclusive-OR operator. - Alex Ratushnyak, May 06 2012

a(n+1) = Sum_{k=0..n} A106344(n,k)*4^(n-k). - 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

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Last modified November 30 13:47 EST 2021. Contains 349420 sequences. (Running on oeis4.)