User:Robert Dickau

Amateur; owner of an unused B.S. in Mathematics and M.S. in Actuarial Science.

Indirect contributor of figures (through links) to:

• A000045: Fibonacci numbers
• A000108: Catalan numbers
• A000142: factorials
• A000110 and A084423: Bell numbers
• A000984: central binomial coefficients
• A001006: Motzkin numbers
• A008277 and A048993: Stirling numbers of the second kind
• A000166 and A100015: derangements
• A001008, A002805, and A065071: harmonic numbers
• A008275 and A048994: Stirling numbers of the first kind
• A001850: Delannoy numbers
• A006480: De Bruijn's s(3,n)
• A008977: $(4n)!/(n!)^{4}$
• A008978: $(5n)!/(n!)^{5}$

Listed as author (though S. S. Gupta beat me to it by 20+ years) of A019566: Unique numbers: $1-1$, $21-12$, $321-123$, ..., $10987654321-12345678910$.