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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A283034 Numbers n such that n = (sum of digits of n)^(last digit of n). 0
1, 4913, 19683, 52521875, 24794911296, 68719476736, 271818611107, 1174711139837 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

The check must be done up to 10^22 (then for 23 digits in a number max result can be (23*10)^9=4,6*10^20<10^22).

LINKS

Table of n, a(n) for n=1..8.

EXAMPLE

1=1^1, 4913=(4+9+1+3)^3, 19683=(1+9+6+8+3)^3, 52521875=(5+2+5+2+1+8+7+5)^5

MATHEMATICA

Union[Reap[nd=1; Sow[1]; While[Ceiling[(10^(nd-1))^(1/9)] <= 9 nd, Do[ Do[v = s^e; If[Mod[v, 10] == e && Plus @@ IntegerDigits@ v == s, Sow[v]], {s, Ceiling[ (10^(nd-1))^(1/e)], Min[ Floor[10^(nd/e)], 9 nd]}], {e, 2, 9}]; nd++]][[2, 1]]] (* all terms, Giovanni Resta, Feb 27 2017 *)

PROG

(VBA)

Sub calcul()

Sheets("Result").Select

Range("A1").Select

For i = 1 To 10000000

Sum = 0

For k = 1 To Len(i)

Sum = Sum + Mid(i, k, 1)

Next

If Sum ^Mid(i, len(i), 1)= i Then

ActiveCell.Value = i

ActiveCell.Offset(1, 0).Select

End If

Next

End Sub

CROSSREFS

Cf. A007953, A010879, A023106.

Sequence in context: A179144 A036530 A088069 * A114770 A013807 A013884

Adjacent sequences:  A283031 A283032 A283033 * A283035 A283036 A283037

KEYWORD

nonn,base,fini,full

AUTHOR

Shmelev Aleksei, Feb 27 2017

EXTENSIONS

a(5)-a(8) from Giovanni Resta, Feb 27 2017

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 October 21 11:30 EDT 2019. Contains 328295 sequences. (Running on oeis4.)