Annual Appeal: Please make a donation (tax deductible in USA) to keep the OEIS running. Over 5000 articles have referenced us, often saying "we discovered this result with the help of the OEIS".
A131644(a(n)) = n and A131644(m) <> n for m < a(n).
Reinhard Zumkeller, Table of n, a(n) for n = 0..86
import Data.List (elemIndex); import Data.Maybe (fromJust)
a192362 = (+ 1) . fromJust . (`elemIndex` a131644_list)
-- Reinhard Zumkeller, Jan 30 2015
Cf. A131644, A241582, A241583.
Sequence in context: A128369 A087568 A087564 * A057776 A110362 A074478
Adjacent sequences: A192359 A192360 A192361 * A192363 A192364 A192365
Reinhard Zumkeller, Jun 30 2011
Better definition from N. J. A. Sloane, May 06 2014