1,5

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

F. Harary and E. M. Palmer, Graphical Enumeration, Academic Press, NY, 1973, p. 117.

Valery A. Liskovets, Enumeration of Euler graphs. (Russian), Vesci Akad. Navuk BSSR, Ser. Fiz.-Mat. Navuk 1970, No.6, 38-46 (1970). Math. Rev., Vol. 44, 1972, p. 1195, #6557.

R. W. Robinson, Enumeration of Euler graphs, pp. 147-153 of F. Harary, editor, Proof Techniques in Graph Theory. Academic Press, NY, 1969.

R. W. Robinson, personal communication.

R. W. Robinson, Numerical implementation of graph counting algorithms, AGRC Grant, Math. Dept., Univ. Newcastle, Australia, 1979.

R. W. Robinson, Table of n, a(n) for n = 1..26

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

Erich Friedman, Illustration of initial terms

Brendan McKay, Combinatorial Data (Eulerian graphs)

Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics.

Let B(x) = g.f. for A002854. Then g.f. A(x) for A003049 satisfies 1+B(x) = exp( Sum_{n=1..inf} A(x^n)/n) - Robinson (1969).

Inverse Euler transform of A002854. (This is equivalent to the Robinson formula.) - Frank Adams-Watters (FrankTAW(AT)Netscape.net), Jul 24 2006

Cf. A002854.

Sequence in context: A100214 A047710 A063580 this_sequence A098563 A032301 A032213

Adjacent sequences: A003046 A003047 A003048 this_sequence A003050 A003051 A003052

nonn,nice,easy

N. J. A. Sloane (njas(AT)research.att.com).

More terms from Vladeta Jovovic (vladeta(AT)eunet.rs), Apr 18 2000