A067779 - OEIS

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A067779

Primes such that the sum of the squares of its digits is equal to the product of its digits.

11353, 13513, 15313, 15331, 31153, 31513, 31531, 33151, 35311, 51133, 53113, 1125221, 1212251, 1212521, 1221251, 1252211, 1512221, 2115221, 2122151, 2122511, 2151221, 2152211, 2215211, 2221511, 2251121, 2251211, 5122121

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Table of n, a(n) for n=1..27.

EXAMPLE

An eight-digit term is 11224121, a ten-digit term is 1111111843.

11353 belongs to the sequence because 1^2+1^2+3^2+5^2+3^2=45=1*1*3*5*3

PROG

(PARI) forprime(p=2, 6e6, n=p; sd=0; pd=1; while(n>0, d=divrem(n, 10); n=d[1]; sd=sd+d[2]*d[2]; pd=pd*d[2]); if(sd==pd, print1(p, ", ")))

CROSSREFS

Sequence in context: A179917 A287245 A067791 * A202377 A210122 A364717

Adjacent sequences: A067776 A067777 A067778 * A067780 A067781 A067782

KEYWORD

easy,nonn,base

AUTHOR

Felice Russo, Feb 06 2002

EXTENSIONS

Edited and extended by Klaus Brockhaus Feb 11 2002

STATUS

approved