The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A257692 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing entries 1-10 | older changes

A257692

Numbers such that the smallest nonzero digit present (A257679) in their factorial base representation is 2.
(history; published version)

#19 by Joerg Arndt at Wed Feb 14 01:05:25 EST 2024

STATUS

reviewed

approved

#18 by Michel Marcus at Wed Feb 14 00:29:45 EST 2024

STATUS

proposed

reviewed

#17 by Amiram Eldar at Wed Feb 14 00:15:30 EST 2024

STATUS

editing

proposed

#16 by Amiram Eldar at Wed Feb 14 00:13:37 EST 2024

COMMENTS

Numbers n k for which A257679(nk) = 2.

#15 by Amiram Eldar at Wed Feb 14 00:07:15 EST 2024

CROSSREFS

Cf. A007623, A257679, A257693.

#14 by Amiram Eldar at Wed Feb 14 00:06:54 EST 2024

LINKS

<a href="/index/Fa#facbase">Index entries for sequences related to factorial base representation</a>.

MATHEMATICA

q[n_] := Module[{k = n, m = 2, r, s = {}}, While[{k, r} = QuotientRemainder[k, m]; k != 0|| r != 0, AppendTo[s, r]; m++]; !MemberQ[s, 1] && MemberQ[s, 2]]; Select[Range[500], q] (* Amiram Eldar, Feb 14 2024 *)

KEYWORD

nonn,base

STATUS

approved

editing

#13 by Joerg Arndt at Thu May 06 11:04:39 EDT 2021

STATUS

reviewed

approved

#12 by Michel Marcus at Thu May 06 10:30:39 EDT 2021

STATUS

proposed

reviewed

#11 by F. Chapoton at Thu May 06 10:13:08 EDT 2021

STATUS

editing

proposed

#10 by F. Chapoton at Thu May 06 10:13:01 EDT 2021

PROG

def A(n, p=2): return n if n<p else A(int(n//p), , p+1)*10 + n%p

print ([n for n in range(1, 503) if a(n)==2] ) # Indranil Ghosh, Jun 19 2017

STATUS

approved

editing

Discussion

Thu May 06

10:13

F. Chapoton: adapt py code to py3