A193422 Smallest number m such that A193358(m) = n.

0, 1, 4, 2, 10, 6, 18, 12, 28, 20, 40, 30, 54, 42, 70, 56, 88, 72, 108, 90, 130, 110, 154, 132, 180, 156, 208, 182, 238, 210, 270, 240, 304, 272, 340, 306, 378, 342, 418, 380, 460, 420, 504, 462, 550, 506, 598, 552, 648, 600, 700, 650, 754, 702, 810, 756

Offset

1,3

Comments

A193358(a(n)) = n and A193358(m) <> n for m < a(n).

Links

Reinhard Zumkeller, Table of n, a(n) for n = 1..1000

Formula

From Chai Wah Wu, Jun 07 2016: (Start)

G.f.: x^2*(1 + 3*x - 4*x^2 + 2*x^3 + x^4 - x^5)/((1 - x)^3*(1 + x)^2).

a(2*n) = n*(n-1) for n > 1.

a(2*n+1) = n*(n+3).

a(n) = a(n-1) + 2*a(n-2) - 2*a(n-3) - a(n-4) + a(n-5) for n > 7. (End)

Prog

(Haskell)
import Data.List (elemIndex)
import Data.Maybe (fromJust)
a193422 n = a193422_list !!(n-1)
a193422_list = map (fromJust . (`elemIndex` a193358_list)) [1..]

Crossrefs

Sequence in context: A283943 A283942 A266418 * A357595 A160572 A213500

Adjacent sequences: A193419 A193420 A193421 * A193423 A193424 A193425

Keyword

nonn,easy

Author

Reinhard Zumkeller, Jul 27 2011

Status

approved