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A078503 a(n) = binomial(phi(n+1),phi(n)). 0
1, 2, 1, 6, 0, 15, 0, 15, 0, 210, 0, 495, 0, 28, 1, 12870, 0, 18564, 0, 495, 0, 646646, 0, 125970, 0, 18564, 0, 30421755, 0, 5852925, 0, 4845, 0, 735471, 0, 1251677700, 0, 134596, 0, 62852101650, 0, 11058116888, 0, 10626, 0, 7890371113950, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
MATHEMATICA
Table[Binomial[EulerPhi[i + 1], EulerPhi[i]], {i, 1, 50}]
CROSSREFS
Cf. A000010.
Sequence in context: A155183 A211173 A163553 * A288052 A288505 A097407
KEYWORD
nonn
AUTHOR
Joseph L. Pe, Jan 05 2003
STATUS
approved

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Last modified February 24 14:59 EST 2024. Contains 370305 sequences. (Running on oeis4.)