login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A187740 G.f.: Sum_{n>=0} (5*n+1)^n * x^n / (1 + (5*n+1)*x)^n. 8
1, 6, 85, 1650, 40500, 1200000, 41625000, 1653750000, 74025000000, 3685500000000, 201993750000000, 12084187500000000, 783523125000000000, 54729675000000000000, 4097124281250000000000, 327237848437500000000000, 27775310062500000000000000, 2496585341250000000000000000 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
LINKS
FORMULA
a(n) = (5*n+7) * 5^(n-1) * n!/2 for n>0 with a(0)=1.
E.g.f.: (2 - 8*x + 15*x^2) / (2*(1-5*x)^2).
EXAMPLE
G.f.: A(x) = 1 + 6*x + 85*x^2 + 1650*x^3 + 40500*x^4 + 1200000*x^5 +...
where
A(x) = 1 + 6*x/(1+6*x) + 11^2*x^2/(1+11*x)^2 + 16^3*x^3/(1+16*x)^3 + 21^4*x^4/(1+21*x)^4 + 26^5*x^5/(1+26*x)^5 +...
PROG
(PARI) {a(n)=polcoeff(sum(m=0, n, ((5*m+1)*x)^m/(1+(5*m+1)*x +x*O(x^n))^m), n)}
for(n=0, 20, print1(a(n), ", "))
CROSSREFS
Sequence in context: A164266 A136597 A064329 * A332407 A358297 A209035
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Jan 03 2013
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 18 10:01 EDT 2024. Contains 371779 sequences. (Running on oeis4.)