The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A121041

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

A121041

Number of divisors of n that are also contained in the decimal representation of n.
(history; published version)

#31 by N. J. A. Sloane at Mon Feb 26 10:10:10 EST 2024

STATUS

reviewed

approved

#30 by Joerg Arndt at Mon Feb 26 09:40:49 EST 2024

STATUS

proposed

reviewed

#29 by Joerg Arndt at Mon Feb 26 09:40:46 EST 2024

STATUS

editing

proposed

#28 by Joerg Arndt at Mon Feb 26 09:40:43 EST 2024

COMMENTS

a(n) = 1 iff A121042(n) = n.

a(A155005(n)) = n and a(m) < n for m < A155005(n). - Reinhard Zumkeller, Jan 18 2009

FORMULA

a(n) = 1 iff A121042(n) = n.

a(A155005(n)) = n and a(m) < n for m < A155005(n). - Reinhard Zumkeller, Jan 18 2009

STATUS

proposed

editing

#27 by Paolo Xausa at Mon Feb 26 09:25:12 EST 2024

STATUS

editing

proposed

#26 by Paolo Xausa at Mon Feb 26 09:25:07 EST 2024

MATHEMATICA

A121041[n_] := DivisorSum[n, 1 &, StringContainsQ[IntegerString[n], IntegerString[#]] &]; Array[A121041, 150] (* _Paolo Xausa_, Feb 25 2024 *)

Array[A121041, 150] (* Paolo Xausa, Feb 25 2024 *)

STATUS

proposed

editing

#25 by Paolo Xausa at Mon Feb 26 09:17:38 EST 2024

STATUS

editing

proposed

#24 by Paolo Xausa at Mon Feb 26 09:17:10 EST 2024

MATHEMATICA

A121041[n_] := DivisorSum[n, 1 &, StringContainsQ[IntegerString[n], ToStringIntegerString[#]] &];

#23 by Paolo Xausa at Mon Feb 26 09:15:45 EST 2024

MATHEMATICA

A121041[n_] := DivisorSum[n, 1 &, StringContainsQ[ToStringIntegerString[n], ToString[#]] &];

STATUS

approved

editing

#22 by Michael De Vlieger at Sun Feb 25 21:07:54 EST 2024

STATUS

reviewed

approved