The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A190997 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing entries 1-10 | older changes

A190997

Product of digits of all the divisors of n.
(history; published version)

#19 by Harvey P. Dale at Sun Nov 27 18:57:42 EST 2022

STATUS

editing

approved

#18 by Harvey P. Dale at Sun Nov 27 18:57:39 EST 2022

MATHEMATICA

Table[Times@@Flatten[IntegerDigits/@Divisors[n]], {n, 100}] (* Harvey P. Dale, Nov 27 2022 *)

STATUS

approved

editing

#17 by Bruno Berselli at Fri Sep 23 05:03:12 EDT 2016

STATUS

reviewed

approved

#16 by Joerg Arndt at Fri Sep 23 04:50:21 EDT 2016

STATUS

proposed

reviewed

#15 by Joerg Arndt at Fri Sep 23 04:50:12 EDT 2016

STATUS

editing

proposed

#14 by Joerg Arndt at Fri Sep 23 04:50:08 EDT 2016

PROG

(PARI) a007954(n) = my(d=digits(n)); prod(i=1, #d, d[i]);

STATUS

proposed

editing

#13 by Michel Marcus at Thu Sep 22 15:37:08 EDT 2016

STATUS

editing

proposed

Discussion

Thu Sep 22

15:41

Michel Marcus: I mean sumdiv

15:53

Felix Fröhlich: I can't seem to get fordiv to work. What is the meaning of the arguments of that function? It appears to expect three arguments?

15:56

Felix Fröhlich: Ah, okay, but why sumdiv?

#12 by Michel Marcus at Thu Sep 22 15:36:12 EDT 2016

MAPLE

A190997:=proc(n) local d, i, p: d:=numtheory[divisors](n): p:=1: for i from 1 to nops(d) do p:=p*mul(d, d=convert(d[i], base, 10)): od: return p: end: seq(A190997(n), n=1..57); # _Nathaniel Johnston, _, Jun 15 2011

STATUS

proposed

editing

Discussion

Thu Sep 22

15:37

Michel Marcus: Or you could have used fordiv

#11 by Felix Fröhlich at Thu Sep 22 15:16:00 EDT 2016

STATUS

editing

proposed

#10 by Felix Fröhlich at Thu Sep 22 15:13:01 EDT 2016

PROG

(PARI) a007954(n) = my(d=digits(n)); prod(i=1, #d, d[i])

a(n) = my(div=divisors(n), pdt=1); for(k=1, #div, pdt=pdt*a007954(div[k])); pdt \\ Felix Fröhlich, Sep 22 2016

STATUS

approved

editing