0,3

a(n+1) is the permanent of the n X n matrix M with M(i,i) = i+1, other entries 1 . - Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Nov 03 2005

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

J. Ginsburg, Iterated exponentials, Scripta Math., 11 (1945), 340-353.

T. D. Noe, Table of n, a(n) for n=0..100

P. J. Cameron, Sequences realized by oligomorphic permutation groups, J. Integ. Seqs. Vol. 3 (2000), #00.1.5.

INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 34

INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 298

Sum_{k=1..n} (k-1)!*|Stirling1(n, k)|. - Vladeta Jovovic (vladeta(AT)eunet.rs), Sep 14 2003

a(n+1) = n! * Sum_{k=0..n} A007840(k)/k!. E.g. a(4) = 228 = 24*(1/1+1/1+3/2+14/6+88/24) = 24+24+36+56+88. - DELEHAM Philippe (kolotoko(AT)wanadoo.fr), Dec 10 2003

series(ln(1/(1+ln(1-x))), x, 17);

with (combstruct): M[ 1798 ] := [ A, {A=Cycle(Cycle(Z))}, labeled ]:

Log[ 1/(1+Log[ 1-x ]) ]

(PARI) a(n)=if(n<0, 0, n!*polcoeff(-log(1+log(1-x+x*O(x^n))), n))

a(n)=|A039814(n, 1)| (first column of triangle). Cf. A000268, A000310, A000359, A000406, A001765.

Cf. A007840.

Sequence in context: A006947 A014307 A000154 this_sequence A058129 A101514 A111908

Adjacent sequences: A003710 A003711 A003712 this_sequence A003714 A003715 A003716

nonn,easy,nice

N. J. A. Sloane (njas(AT)research.att.com), R. H. Hardin (rhhardin(AT)att.net), Simon Plouffe (simon.plouffe(AT)gmail.com)

Thanks to Paul Zimmermann for comments.