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calc/help/euler
Landon Curt Noll a31078bbec Remove all RCS @(#) lines and RCS strings
Some folks might think: “you still use RCS”?!?  And we will say,
hey, at least we switched from SCCS to RCS back in … I think it was
around 1994 ... at least we are keeping up! :-) :-) :-)

Logs say that SCCS version 18 became RCS version 19 on 1994 March 18.

RCS served us well.  But now it is time to move on.   And so we are
switching to git.

Calc releases produce a lot of file changes.  In the 125 releases
of calc since 1996, when I started managing calc releases, there
have been 15473 file mods!
2017-05-23 01:33:23 -07:00

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NAME
euler - Euler number
SYNOPSIS
euler(n)
TYPES
n integer, n <= 1000000 if even
return integer
DESCRIPTION
Returns the Euler number with index n, i.e. the coefficient E_n in
the expansion
sech(t) = Sigma E_n * t^n/n!
When euler(n) is computed for positive even n, the values for
n and smaller positive even indices are stored in a table so that
a later call to euler(k) with 0 <= k <= n will be executed quickly.
If euler(k) is called with negative k, zero is returned and the
memory used by the table iu freed.
Considerable runtime and memery are required for calculating
euler(n) for large even n.
EXAMPLE
; for (n = 0; n <= 6; n++) print euler(n),; print;
1 0 -1 0 5 0 -61
LIMITS
none
LINK LIBRARY
NUMBER *qeuler(long n)
SEE ALSO
bernoulli, bell, catalan, comb, fact, perm
## Copyright (C) 2000 Ernest Bowen
##
## Calc is open software; you can redistribute it and/or modify it under
## the terms of the version 2.1 of the GNU Lesser General Public License
## as published by the Free Software Foundation.
##
## Calc is distributed in the hope that it will be useful, but WITHOUT
## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
## or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
## Public License for more details.
##
## A copy of version 2.1 of the GNU Lesser General Public License is
## distributed with calc under the filename COPYING-LGPL. You should have
## received a copy with calc; if not, write to Free Software Foundation, Inc.
## 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
##
## Under source code control: 2000/12/14 01:33:00
## File existed as early as: 2000
##
## Share and enjoy! :-) http://www.isthe.com/chongo/tech/comp/calc/