OFFSET
1,1
REFERENCES
W. Oberschelp, "Strukturzahlen in endlichen Relationssystemen," in Contributions to Mathematical Logic (Proceedings 1966 Hanover Colloquium), pp. 199-213, North-Holland Publ., Amsterdam, 1968.
N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
W. Oberschelp, Strukturzahlen in endlichen Relationssystemen, in Contributions to Mathematical Logic (Proceedings 1966 Hanover Colloquium), pp. 199-213, North-Holland Publ., Amsterdam, 1968. [Annotated scanned copy]
FORMULA
a(n) = Sum_{1*s_1+2*s_2+...=n}(fix A[s_1, s_2, ...]/ (1^s_1*s_1!*2^s_2*s_2!*...)) where fix A[s_1, s_2, ...] = 8^Sum_{i, j>=1} (gcd(i,j)*s_i*s_j). - Sean A. Irvine, Nov 20 2016
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
More terms from Sean A. Irvine, Nov 20 2016
STATUS
approved