This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A257766 #22 May 08 2015 15:25:05 %S A257766 1,2023,2400,52215,615627,938600,1648656 %N 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. %C A257766 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 %e A257766 52215 is in the sequence because 52215 = (5+2+2+1+5)*(5^2+2^2+2^2+1^2+5^2)^2. %t A257766 Select[Range@1648656,#==Total[IntegerDigits[#]] *Total[IntegerDigits[#]^2]^2&] (* _Ivan N. Ianakiev_, May 08 2015 *) %Y A257766 Cf. A115518. %K A257766 base,nonn,fini,full %O A257766 1,2 %A A257766 _Pieter Post_, May 07 2015