|
| |
|
|
A095761
|
|
Numbers whose square root shows strings of seemingly rational and irrational strings.
|
|
0
| |
|
|
1, 123, 12345, 1234567, 123456789, 12345679011, 1234567901233, 123456790123455, 12345679012345677, 1234567901234567899, 123456790123456790121, 12345679012345679012343
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,2
|
|
|
COMMENTS
| Definition not clear to me - more information please! - N. J. A. Sloane (njas(AT)research.att.com), Jul 11 2004
|
|
|
REFERENCES
| Related to A014824.
|
|
|
LINKS
| K. S. Brown, Schizophrenic numbers
|
|
|
FORMULA
| a(1) = 1; for n > 1, a(n) = 100*a(n - 1) + 22*n - 21.
O.g.f.: x(1+21x)/[(-1+x)^2*(1-100x)] = -17/[81(-1+x)]-1/[81(-1+100*x)]-2/[9(-1+x)^2] . - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Feb 01 2008
a(n)=-(19/81)-(2/9)*(n-1)+(100/81)*100^(n-1), with n>=1 [From Paolo P. Lava (paoloplava(AT)gmail.com), Sep 26 2008]
|
|
|
EXAMPLE
| a(6) = 100*a(5) + 22*6 - 21 = 100*123456789 + 132 - 21 = 12345679011.
|
|
|
CROSSREFS
| Sequence in context: A068239 A098683 A135479 * A121917 A049670 A181006
Adjacent sequences: A095758 A095759 A095760 * A095762 A095763 A095764
|
|
|
KEYWORD
| easy,nonn,base,obsc
|
|
|
AUTHOR
| Michael Joseph Halm (hierogamous(AT)lycos.com), Jul 10 2004
|
| |
|
|
