The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A225850

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A225850

Inverse of permutation in A167151.
(history; published version)

#17 by Michael De Vlieger at Sat Jun 04 21:17:18 EDT 2022

STATUS

proposed

approved

#16 by Eric Rowland at Sat Jun 04 21:00:11 EDT 2022

STATUS

editing

proposed

#15 by Eric Rowland at Sat Jun 04 21:00:04 EDT 2022

MAPLE

(Scheme)

(define (A225850 n) (if (< n 3) n (- (* 2 (+ (A232747 n) (A232749 n))) (- (A232746 n) (A232746 (- n 1))))))

;; Antti Karttunen, Dec 04 2013

PROG

(Scheme)

(define (A225850 n) (if (< n 3) n (- (* 2 (+ (A232747 n) (A232749 n))) (- (A232746 n) (A232746 (- n 1))))))

;; Antti Karttunen, Dec 04 2013

STATUS

approved

editing

#14 by Andrew Howroyd at Thu Dec 09 11:54:44 EST 2021

STATUS

reviewed

approved

#13 by Michel Marcus at Thu Dec 09 03:55:04 EST 2021

STATUS

proposed

reviewed

#12 by Jean-François Alcover at Thu Dec 09 03:43:52 EST 2021

STATUS

editing

proposed

#11 by Jean-François Alcover at Thu Dec 09 03:43:47 EST 2021

MATHEMATICA

nmax = 100; A5228 = {1};

Module[{d = 2, k = 1}, Do[While[MemberQ[A5228, d], d++]; k += d; d++; AppendTo[A5228, k], {n, 1, nmax}]];

a46[n_] := For[k = 1, True, k++, If[A5228[[k]] > n, Return[k - 1]]];

a47[n_] := If[n == 1, 1, a46[n] (a46[n] - a46[n - 1])];

a48[n_] := a48[n] = If[n == 1, 0, a48[n-1] + (1 - (a46[n] - a46[n-1]))];

a49[n_] := If[n == 1, 0, a48[n] (a48[n] - a48[n - 1])];

a[n_] := If[n < 3, n, 2 (a47[n] + a49[n]) - (a46[n] - a46[n - 1])];

Table[a[n], {n, 0, nmax}] (* Jean-François Alcover, Dec 09 2021 *)

STATUS

approved

editing

#10 by N. J. A. Sloane at Thu Dec 05 08:32:04 EST 2013

STATUS

proposed

approved

#9 by Antti Karttunen at Wed Dec 04 14:45:51 EST 2013

STATUS

editing

proposed

#8 by Antti Karttunen at Wed Dec 04 14:43:48 EST 2013

COMMENTS

For n > 0: A232739(n) = a(A232739(n+1))/2. - Antti Karttunen, Dec 04 2013

CROSSREFS

Inverse permutation: A167151.

Cf. also A005228, A030124, A232739, A232746, A232747, A232749, and also the permutation pair A232751/A232752.

Discussion

Wed Dec 04

14:45

Antti Karttunen: The terms a(0) - A(10000) computed with my Scheme-program match with Zumkeller's b-file.