|
|
A272177
|
|
Alternating row sum of row 2n in A238453.
|
|
0
|
|
|
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
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,3
|
|
COMMENTS
|
The alternating row sums of odd rows in A238453 are 0.
|
|
LINKS
|
|
|
FORMULA
|
a(n) = Sum_{k=0..2n}(-1)^k*A238453(2n,k).
|
|
PROG
|
(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])
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,changed
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|