|
%I #16 Jun 13 2015 00:55:01
%S 39,89,139,189,239,289,339,389,439,489,539,589,639,689,739,789,839,
%T 889,939,989,1039,1089,1139,1189,1239,1289,1339,1389,1439,1489,1539,
%U 1589,1639,1689,1739,1789,1839,1889,1939,1989,2039,2089,2139,2189,2239,2289,2339
%N Numbers with four X's in Roman numerals.
%C All these end in XXXIX.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/RomanNumerals.html">Roman Numerals</a>
%H Wikipedia, <a href="http://en.wikipedia.org/wiki/Roman_numerals">Roman numerals</a>
%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (2,-1).
%F a(n) = 50n - 11. - _Charles R Greathouse IV_, May 06 2014
%e 39 = XXXIX; 89 = LXXXIX.
%p A242181:=n->50*n-11; seq(A242181(n), n=1..50); # _Wesley Ivan Hurt_, May 07 2014
%p [seq(convert(50*n-11, roman), n=1..50)]; # for the Roman version - _Wolfdieter Lang_, May 09 2014
%t Table[50 n - 11, {n, 50}] (* _Wesley Ivan Hurt_, May 07 2014 *)
%o (PARI) a(n)=50*n-11 \\ _Charles R Greathouse IV_, May 06 2014
%Y Cf. A006968.
%K nonn,base,easy
%O 1,1
%A _J. Lowell_, May 06 2014
%E More terms from _Wesley Ivan Hurt_, May 07 2014
|
