A272177 Alternating row sum of row 2n in A238453.
1, 1, 2, 6, 42, 162, 634, 2726, 9330, 37814, 186034, 623934, 2370354, 10505738, 37417658, 113248562, 738713250, 2753640290, 7522970666, 46292418830, 146514514914, 496491671978, 2915741154442, 9464309679414, 39098814277474, 173211426442282, 652232674100690
Offset: 0
Keywords
Links
- Tom Edgar, Totienomial Coefficients, INTEGERS, 14 (2014), #A62.
Programs
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Sage
P=[euler_phi(i) for i in [0..100]] Tr=[[prod(P[1:n+1])/(prod(P[1:k+1])*prod(P[1:(n-k)+1])) for k in [0..n]] for n in [0..len(P)-1]] L=[sum((-1)^i*x[i] for i in [0..len(x)-1]) for x in Tr] print([y for y in L if y!=0])
Formula
a(n) = Sum_{k=0..2n}(-1)^k*A238453(2n,k).
Comments