This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A093783 #25 Feb 16 2025 08:32:53 %S A093783 1,2,3,6,5,6,7,8,11,10,11,12,13,16,15,16,17,18,21,20,21,22,23,26,25, %T A093783 26,27,28,31,30,31,32,33,36,35,36,37,38,41,60,61,62,63,66,65,66,67,68, %U A093783 71,50,51,52,53,56,55,56,57,58,61,60,61,62,63,66,65,66,67,68 %N A093783 Sum of digits of n in Roman numeral representation. %H A093783 Nathaniel Johnston, <a href="/A093783/b093783.txt">Table of n, a(n) for n = 1..3999</a> %H A093783 Stephanus Gibbs, <a href="http://www.softhawkway.com/rcalc.htm">Roman Numeral and Date Conversion</a> %H A093783 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/RomanNumerals.html">Roman Numerals</a> %H A093783 Wikipedia, <a href="http://en.wikipedia.org/wiki/Roman_numerals">Roman numerals</a> %e A093783 n=42 == XLII: a(42) = 'X' + 'L' + 'I' + 'I' = 10+50+1+1 = 62. %p A093783 A093783 := proc(n) local r: r:=convert(n, roman): return add(convert(r[j], arabic), j=1..length(r)): end: seq(A093783(n), n=1..68); # _Nathaniel Johnston_, May 18 2011 %t A093783 Total[#2 FromRomanNumeral[#1] & @@@ Tally[Characters@ RomanNumeral@ #]] & /@ Range@ 68 (* _Michael De Vlieger_, Sep 08 2015, Version 10.2 *) %o A093783 (Haskell) %o A093783 a093783 n = q 0 $ a061493 n where %o A093783 q s 0 = s %o A093783 q s x = q (s + [0,1,5,10,50,100,500,1000] !! d') x' %o A093783 where (x',d) = divMod x 10; d' = fromInteger d %o A093783 -- _Reinhard Zumkeller_, Apr 14 2013 %o A093783 (HP 49G calculator) %o A093783 :: %o A093783 CK1&Dispatch %o A093783 # FF %o A093783 :: %o A093783 FPTR2 ^DupQIsZero? %o A093783 caseSIZEERR %o A093783 FPTR2 ^Z>S %o A093783 Z0_ %o A093783 SWAP %o A093783 DUPLEN$ %o A093783 ZERO_DO %o A093783 DUP %o A093783 ISTOP-INDEX %o A093783 SUB$1# %o A093783 BINT48 %o A093783 #- %o A093783 BINT4 %o A093783 OVER#= %o A093783 OVER %o A093783 BINT9 %o A093783 #= %o A093783 OR %o A093783 IT %o A093783 #2+ %o A093783 FPTR2 ^#>Z %o A093783 Z10_ %o A093783 INDEX@ %o A093783 FPTR2 ^RP# %o A093783 FPTR2 ^RMULText %o A093783 ROT %o A093783 FPTR2 ^RADDext %o A093783 SWAPLOOP %o A093783 DROP %o A093783 ; %o A093783 ; %o A093783 _Gerald Hillier_, Sep 08 2015 %Y A093783 Cf. A007953, A057226, A006968. %Y A093783 Cf. A061493, A002963. %K A093783 nonn,easy,base %O A093783 1,2 %A A093783 _Reinhard Zumkeller_, May 17 2004