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%I #9 Jun 11 2022 16:41:13
%S 0,1,1,3,9,21,111,393,2309,12321,81071,560033,4301109,35526921,
%T 316858231,3025055673,30815437909,333492212321,3821573586591,
%U 46224758487313,588552491006709,7868364598774521,110201454736846151,1613597716238974953,24653957361927031509
%N Boustrophedon transform of the signed Jacobsthal numbers.
%C Boustrophedon transform of (-1)^n*A001045(n). Binomial transform is A101473.
%F E.g.f.: (sec(x)+tan(x))*(exp(x)-exp(-2*x))/3.
%F a(n) ~ n! * (exp(3*Pi/2)-1) * 2^(n+2) / (3 * exp(Pi) * Pi^(n+1)). - _Vaclav Kotesovec_, Jun 12 2015
%o (Python)
%o from itertools import accumulate, islice
%o def A101474_gen(): # generator of terms
%o blist, a, b = tuple(), 0, -1
%o while True:
%o yield (blist := tuple(accumulate(reversed(blist),initial=a)))[-1]
%o a, b = -b, -2*a-b
%o A101474_list = list(islice(A101474_gen(),30)) # _Chai Wah Wu_, Jun 11 2022
%Y Cf. A001045.
%K easy,nonn
%O 0,4
%A _Paul Barry_, Jan 21 2005
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