`scipy.special._basic:euler`

Signature

def euler(n)

Euler numbers E(0), E(1), ..., E(n).

The Euler numbers ^[1] are also known as the secant numbers.

Because euler(n) returns floating point values, it does not give exact values for large n. The first inexact value is E(22).

: ndarray: The Euler numbers [E(0), E(1), ..., E(n)]. The odd Euler numbers, which are all zero, are included.

import numpy as np
from scipy.special import euler
euler(6)

✓

array([  1.,   0.,  -1.,   0.,   5.,   0., -61.])

euler(13).astype(np.int64)

✓

array([      1,       0,      -1,       0,       5,       0,     -61,
             0,    1385,       0,  -50521,       0, 2702765,       0])

euler(22)[-1]  # Exact value of E(22) is -69348874393137901.

✗

np.float64(-6.9348874393137976e+16)