A085446 Numbers divisible by twice the sum of the products of each of their digits, excluding even multiples of 10.

162, 324, 392, 512, 648, 1134, 1296, 1944, 2106, 2592, 2704, 3402, 4212, 4536, 5022, 5184, 5632, 5832, 7128, 7514, 7744, 8424, 8748, 9072, 10044, 10206, 10368, 10406, 11016, 11502, 11664, 12032, 12312, 12716, 13122, 13608, 14256, 14504, 14904

Offset

0,1

Comments

Take a number n, create a table with d columns and rows where d=number of digits of n. Each column corresponds to a digit of n and each row to a digit of n. In each cell, multiply the two digits of n represented by that row and column. Add up the sums of all of the rows and all of the columns to get a new number m which divides n.

Links

Harvey P. Dale, Table of n, a(n) for n = 0..1000

Example

512 / (2*(5*5 + 5*1 + 5*2 + 1*5 + 1*1 + 1*2 + 2*5 + 2*1 + 2*2)) = 4.

Mathematica

Select[Range[15000], !Divisible[#, 10]&&Divisible[#, 2Total[Times @@@ Tuples[ IntegerDigits[#], 2]]]&] (* Harvey P. Dale, Aug 19 2014 *)

Crossrefs

Cf. A085444.

Sequence in context: A259220 A107120 A045010 * A274027 A206210 A044985

Adjacent sequences: A085443 A085444 A085445 * A085447 A085448 A085449

Keyword

base,nonn

Author

Chuck Seggelin (barkeep(AT)plastereddragon.com), Jun 30 2003

Status

approved