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A064450
Sum of totients of binomial coefficients C(n,j), j=0..n.
2
1, 2, 3, 6, 8, 18, 30, 86, 106, 158, 290, 662, 1410, 3674, 7166, 16242, 20242, 46754, 72910, 162686, 304866, 524570, 1179430, 2842710, 5230210, 11035402, 24478394, 40473686, 63927602, 155016682, 328928338, 888801182, 928681474, 1765045802
OFFSET
0,2
COMMENTS
a(n) = sum of n-th row of the triangle formed by replacing each m in Pascal's triangle by phi(m). See A102715.
LINKS
EXAMPLE
For n=4, the binomial coefficients C(4,j) are 1, 4, 6, 4, and 1. The totients are 1, 2, 2, 2, and 1. So a(4) = 1 + 2 + 2 + 2 + 1 = 8. - Michael B. Porter, Jun 25 2018
MATHEMATICA
a(n)=Apply[Plus, Table[EulerPhi[Binomial[n, w]], {w, 0, n}]],
PROG
(PARI) a(n) = vecsum(vector(n+1, k, eulerphi(binomial(n, k-1)))); \\ Michel Marcus, Jun 24 2018
CROSSREFS
Sequence in context: A005508 A022542 A220418 * A217137 A248824 A130623
KEYWORD
nonn
AUTHOR
Labos Elemer, Oct 02 2001
STATUS
approved