OFFSET
0,2
LINKS
FORMULA
(10^(n+1) - 7^(n+1))/3. - Lambert Klasen (lambert.klasen(AT)gmx.net), Feb 05 2005
a(n) = 10*a(n-1) + 7^n, a(0)=1. - Vincenzo Librandi, Feb 09 2011
a(n) = 17*a(n-1) - 70*a(n-2), a(0)=1, a(1)=17. - Vincenzo Librandi, Feb 09 2011
MATHEMATICA
Join[{a=1, b=17}, Table[c=17*b-70*a; a=b; b=c, {n, 40}]] (* Vladimir Joseph Stephan Orlovsky, Feb 09 2011 *)
CoefficientList[Series[1/((1-7x)(1-10x)), {x, 0, 30}], x] (* or *) LinearRecurrence[ {17, -70}, {1, 17}, 30] (* Harvey P. Dale, Nov 16 2020 *)
PROG
(PARI) for(n=1, 10, print1((10^n-7^n)/3, ", "))
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved