A205084 a(n)=n 4's sandwiched between two 1's.

11, 141, 1441, 14441, 144441, 1444441, 14444441, 144444441, 1444444441, 14444444441, 144444444441, 1444444444441, 14444444444441, 144444444444441, 1444444444444441, 14444444444444441, 144444444444444441, 1444444444444444441, 14444444444444444441

Offset

0,1

Links

Table of n, a(n) for n=0..18.

Index entries for linear recurrences with constant coefficients, signature (11,-10).

Formula

a(0)=11, a(n)=10*a(n-1)+31.

a(n) = (130*10^n-31)/9 (see PARI's code by Charles R Greathouse IV).

Mathematica

a[0]=11; a[n_]:=a[n-1]*10+31; Table[a[n], {n, 0, 44}]

Prog

(PARI) a(n)=(130*10^n-31)/9 \\ Charles R Greathouse IV, Jan 23 2012

Crossrefs

Sequence in context: A024296 A324084 A141907 * A083078 A048965 A218502

Adjacent sequences: A205081 A205082 A205083 * A205085 A205086 A205087

Keyword

nonn,easy,base,less

Author

José María Grau Ribas, Jan 22 2012

Status

approved