

A257766


Numbers n such that the sum of the digits of n times the square of the sum of the digits squared of n equals n.


2




OFFSET

1,2


COMMENTS

Sequence is finite since it cannot contain numbers of 9 or more digits. Indeed a number of 9 digits is at least equal to 10^8, but the function computed here for a number of n digits is at most (9*n)*(9^2*n)^2, which for n=9 is 43046721 < 10^8.  Giovanni Resta, May 08 2015


LINKS

Table of n, a(n) for n=1..7.


EXAMPLE

52215 is in the sequence because 52215 = (5+2+2+1+5)*(5^2+2^2+2^2+1^2+5^2)^2.


MATHEMATICA

Select[Range@1648656, #==Total[IntegerDigits[#]] *Total[IntegerDigits[#]^2]^2&] (* Ivan N. Ianakiev, May 08 2015 *)


CROSSREFS

Cf. A115518.
Sequence in context: A119423 A176913 A013687 * A126821 A333057 A156855
Adjacent sequences: A257763 A257764 A257765 * A257767 A257768 A257769


KEYWORD

base,nonn,fini,full


AUTHOR

Pieter Post, May 07 2015


STATUS

approved



