login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A316943 Numbers k that are a substring of (k-1)*k*(k+1). 1
32, 50, 56, 500, 782, 792, 1165, 5000, 5111, 7484, 8933, 23927, 31623, 46271, 50000, 53257, 64164, 65137, 66995, 78313, 86181, 98442, 316228, 405927, 500000, 803633, 1939055, 1969394, 2133896, 2438170, 3162278, 4039599, 4150015, 5000000, 5354867, 5887042, 6249997 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Any number of the form 5*10^m, with m>0, is part of the sequence.

LINKS

Paolo P. Lava, Table of n, a(n) for n = 1..74

EXAMPLE

31*32*33 = 32736 and 32 is a substring, so it is in the sequence.

5110*5111*5112 = 133511177520 and 5111 is a substring, so it is in the sequence.

MAPLE

P:=proc(q) local k, n; for n from 1 to q do

for k from 1 to ilog10((n-1)*n*(n+1))-ilog10(n)+1 do

if n=trunc((n-1)*n*(n+1)/10^(k-1)) mod 10^(ilog10(n)+1)

then print(n); break; fi; od; od; end: P(10^8);

MATHEMATICA

Select[Range[10^5], SequenceCount @@ Map[IntegerDigits, {(# - 1) # (# + 1), #}] > 0 &] (* Michael De Vlieger, Jul 20 2018 *)

Select[Range[63*10^5], SequenceCount[IntegerDigits[#^3-#], IntegerDigits[#]]>0&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Dec 26 2018 *)

CROSSREFS

Cf. A305670, A316263.

Sequence in context: A259765 A256521 A037008 * A099048 A176542 A048734

Adjacent sequences:  A316940 A316941 A316942 * A316944 A316945 A316946

KEYWORD

nonn,base

AUTHOR

Paolo P. Lava, Jul 17 2018

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 18 15:54 EDT 2019. Contains 326108 sequences. (Running on oeis4.)