A153500 First 3 terms coincide with A152756. For n>3, a(n) is the palindromic number formed from concatenation of 1, 0, A147759(n-3), 0, A147759(n-3), 0 and 1.
1, 101, 10001, 1010101, 101101101, 10101010101, 1010010100101, 101010101010101, 10101101010110101, 1010101010101010101, 101010010101010010101, 10101010101010101010101, 1010101101010101011010101, 101010101010101010101010101, 10101010010101010101001010101
Offset: 1
Examples
n ............ a(n) 1 ............. 1 2 ............ 101 3 ........... 10001 4 .......... 1010101 5 ......... 101101101 6 ........ 10101010101 7 ....... 1010010100101 8 ...... 101010101010101 9 ..... 10101101010110101 10 ... 1010101010101010101 ====================================== Another visualization of the structure ====================================== 1 ............. * 2 ............ /.\ 3 ........... /...\ 4 .......... /.*.*.\ 5 ......... /./|.|\.\ 6 ........ /./.|.|.\.\ 7 ....... /./..|.|..\.\ 8 ...... /./.*.|.|.*.\.\ 9 ..... /././|.|.|.|\.\.\ 10 ... /././.|.|.|.|.\.\.\
Links
- Index entries for linear recurrences with constant coefficients, signature (101,-1110,102010,-111000,1010000,-1000000).
Formula
a(n) = 101*a(n-1)-1110*a(n-2)+102010*a(n-3)-111000*a(n-4)+1010000*a(n-5)-1000000*a(n-6), n>7. [R. J. Mathar, Feb 20 2009]
G.f.: -x*(1000000*x^6-1010000*x^5+10000*x^4-10100*x^3-910*x^2-1) / ((x-1)*(100*x-1)*(10*x^2+1)*(1000*x^2+1)). [Colin Barker, Sep 17 2013]
Extensions
More terms from R. J. Mathar, Feb 20 2009
Keyword:base added by Charles R Greathouse IV, Apr 26 2010
More terms from Colin Barker, Sep 17 2013
Comments