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

 

Logo

Annual appeal: Please make a donation to keep the OEIS running! Over 6000 articles have referenced us, often saying "we discovered this result with the help of the OEIS".
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A088116 Let n = abc..., where a, b, c, are digits of n. a(n) = a*bc...+b*ac...+c*ab...+..., i.e., a(n) = sum, over all the digits, of the product (number obtained by deleting a digit multiplied by the deleted digit). 2
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 0, 6, 12, 18, 24, 30, 36, 42, 48, 54, 0, 8, 16, 24, 32, 40, 48, 56, 64, 72, 0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 0, 12, 24, 36, 48, 60, 72, 84, 96, 108, 0, 14, 28, 42, 56, 70, 84, 98 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,12

COMMENTS

First 100 terms ( for all two digit numbers) match with that of A069816. a(10a + b) = 2ab = (a+b)^2 - (a^2 + b^2)= A069816(10a + b).

LINKS

Table of n, a(n) for n=1..78.

EXAMPLE

a(1234) = 234 + 2*134 + 3*124 + 4*123 = 1366.

CROSSREFS

Cf. A069816, A088117.

Cf. A087346.

Sequence in context: A241142 A271907 A069816 * A100817 A074157 A076309

Adjacent sequences:  A088113 A088114 A088115 * A088117 A088118 A088119

KEYWORD

base,easy,nonn

AUTHOR

Amarnath Murthy, Sep 25 2003

EXTENSIONS

More terms from David Wasserman, May 10 2005

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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified November 21 05:01 EST 2017. Contains 294988 sequences.