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Martin Cohen is a retired computer programmer who loves dancing (favorites are West Coast Swing, Waltz, Foxtrot, and Salsa), writing (but not revising) poems, and solving math problems (that's why I'm here). He is currently trying to learn improv at the Westside Comedy Theater (westsidecomedy.com) in Santa Monica, CA.

He can also be reached at mjcohen@acm.org.


21h
comment Writing $1+3x^2+8x^4+21x^6+\cdots$ as a power series representation
As a rational function.
21h
answered Writing $1+3x^2+8x^4+21x^6+\cdots$ as a power series representation
1d
awarded  Constituent
Dec
18
comment Cantor Pairing Function
Your are right. Duh.
Dec
18
comment how to factor this expressiion
What is over x? What is raised to the second power? Do you mean $\frac{2x^2-4x}{x}+10$?
Dec
18
comment Cantor Pairing Function
Have you compared the two functions? Maybe they both work.
Dec
18
comment How many non-rational complex numbers $x$ have the property that $x^n$ and $(x+1)^n$ are rational?
How about $x^n$ and $(x+a)^n$ for some integer $a$?
Dec
17
comment solve $y'=ay+b$
Reminds me of the Laplace transform.
Dec
17
comment Easier way to solve $\int_0^1 \frac{dx}{\lfloor{}1-\log_2(x)\rfloor}$
I don't think that your way is tedious - it is clever. I think you ought to add your proof (either to the question or as an answer).
Dec
17
answered Distinct Mersenne numbers are coprime
Dec
17
revised Probability of ultimate extinction? Need to show that an infinite series is less than $1$
additional generality
Dec
17
answered Probability of ultimate extinction? Need to show that an infinite series is less than $1$
Dec
17
comment Solving $\sinh(ax) = bx$
email me at mjcohen@acm.org and I'll send it as a reply.
Dec
16
answered Solving $\sinh(ax) = bx$
Dec
16
comment How to prove that the problem cannot be solved by the four Arithmetic Operations?
Wow! Wow! Wow!!
Dec
16
answered How many numbers less than $x$ have a prime factor that is not $2$ or $3$
Dec
16
answered Show that $x\cdot x(k) = x(k+1) + k\cdot x(k)$
Dec
16
comment Finding whether the quadrilateral is cyclic or not
See if the perpendicular bisectors from AB and BC meet on AC and their lengths are the same - that would be the center of an inscribed circle.
Dec
15
comment Am I doing this approximation correctly? (least squares method)
Looks like a square wave. Its Fourier transform is well known.
Dec
15
comment Am I doing this approximation correctly? (least squares method)
Have you plotted the two to see how they look?