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 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
 1, 2023, 2400, 52215, 615627, 938600, 1648656 (list; graph; refs; listen; history; text; internal format)
 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 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

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Last modified May 18 09:26 EDT 2021. Contains 343995 sequences. (Running on oeis4.)