login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A036746 Numbers with "long" representations in Roman notation: given by last n letters from ...MMMDCCCLXXXVIII. 7
1, 2, 3, 8, 18, 28, 38, 88, 188, 288, 388, 888, 1888, 2888, 3888 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Also: Least number using n symbols when written as Roman numeral, cf. A006968 and A061493. One could prefix a conventional a(0)=0. - M. F. Hasler, Jan 12 2015

LINKS

Table of n, a(n) for n=1..15.

Gerard Schildberger, The first 3999 numbers in Roman numerals.

FORMULA

a(n) = min{ k>0 | A006968(k)=n }. - M. F. Hasler, Jan 12 2015

MATHEMATICA

(* assign the 3999 Roman numerals to the variable 'lst' so that lst = {I, II, III, ... MMMCMXCVII, MMMCMXCVIII, MMMCMXCIX}, e.g. using the link to Schildberger's file, then *) f[1] = 1; f[n_] := Block[{k = 2}, While[ StringLength@ SymbolName@ lst[[k]] != n, k++ ]; k]; Array[f, 15] (* Checked by Robert G. Wilson v, Aug 13 2008; edited by M. F. Hasler, Jan 12 2015 *)

PROG

(Haskell)

import Data.List (inits, elemIndex)

import Data.Maybe (mapMaybe)

a036746 n = a036746_list !! (n-1)

a036746_list = map (+ 1) $ mapMaybe (`elemIndex` a061493_list)

   (map (read . reverse) $ tail $ inits $ reverse $ show $ a061493 3888)

-- Reinhard Zumkeller, Apr 14 2013

(PARI) A036746(n)=(n%4+8/9)\.1^(n\4) \\ M. F. Hasler, Jan 12 2015

CROSSREFS

Cf. A061493, A006968, A003587.

Sequence in context: A290878 A096254 A091765 * A232165 A129955 A034066

Adjacent sequences:  A036743 A036744 A036745 * A036747 A036748 A036749

KEYWORD

nonn,base

AUTHOR

J. H. Conway

EXTENSIONS

Checked by Robert G. Wilson v, Aug 13 2008

Edited by M. F. Hasler, Jan 12 2015

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 28 22:03 EDT 2020. Contains 337417 sequences. (Running on oeis4.)