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A292792
The imaginary part of E(2n, i)/i, where E(n, x) is the Euler polynomial.
2
-1, 3, -11, 63, -571, 7623, -140531, 3417183, -105946891, 4079170743, -190947551651, 10679561580303, -703342782666811, 53875223570677863, -4749070236390684371, 477331966210918815423, -54264228263241408276331, 6927625954707653092264983, -986892857756676619338994691
OFFSET
1,2
COMMENTS
The real part is +- 1.
For E(2n-1, i) see A292791.
a(2n) == 3 (mod 6),
a(4n+1) == 5 (mod 6),
a(4n+3) == 1 (mod 6).
Inspired by A291897.
Also the negative imaginary part of E(2n, 1+i) or the imaginary part of E(2n, 1-i).
LINKS
EXAMPLE
a(3) = -11 since E(6, i) = -1 - 11i.
MATHEMATICA
f[n_] := (EulerE[2n, I] - I^(2n))/I; Array[f, 19]
CROSSREFS
Sequence in context: A261919 A232617 A326092 * A199135 A096655 A030226
KEYWORD
sign
AUTHOR
Robert G. Wilson v, Sep 23 2017
STATUS
approved