

A270393


Another variant of narcissistic numbers: integers n equal the product of squared digits of n divided by the sum of digits of n, i.e., n = A007954(n)^2/A007953(n).


0



1, 2, 3, 4, 5, 6, 7, 8, 9, 36, 735
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,2


COMMENTS

No other terms below 10^300.  Max Alekseyev, May 31 2018


LINKS

Table of n, a(n) for n=1..11.


EXAMPLE

36 is a term because 36 = (3^2*6^2)/(3+6).
735 is a term because 735 = (7^2*3^2*5^2)/(7+3+5).


MATHEMATICA

Select[Range[10^6], Function[k, k == Apply[Times, #^2]/(Total@ #) &@ IntegerDigits@ k]@ # &] (* Michael De Vlieger, Mar 16 2016 *)


PROG

(PARI) { is_A270393(n) = my(d = digits(n)); n == vecprod(d)^2/vecsum(d); } \\ Michel Marcus, Mar 17 2016


CROSSREFS

Subsequence of A128606.
Cf. A005188, A257554.
Sequence in context: A080161 A345405 A257554 * A257787 A098771 A276810
Adjacent sequences: A270390 A270391 A270392 * A270394 A270395 A270396


KEYWORD

nonn,more,base


AUTHOR

José de Jesús Camacho Medina, Mar 16 2016


STATUS

approved



