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A039751

Number of n-node graphs containing a 4-cycle.

0, 0, 0, 0, 3, 16, 112, 927, 11995, 273438, 12000099, 1018972683, 165091020547, 50502030251549, 29054155647335623, 31426485969699328399, 64001015704526239877379, 245935864153532913256188013, 1787577725145611700213913518632, 24637809253125004524376347209365832

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,5

REFERENCES

F. Harary and E. M. Palmer, Graphical Enumeration, Academic Press, NY, 1973, p. 228.

LINKS

Table of n, a(n) for n=0..19.

FORMULA

a(n) = A000088(n) - A006786(n). - Falk Hüffner, Nov 27 2015

MATHEMATICA

A000088 = Cases[Import["https://oeis.org/A000088/b000088.txt", "Table"], {_, _}][[All, 2]];

A006786 = Cases[Import["https://oeis.org/A006786/b006786.txt", "Table"], {_, _}][[All, 2]];