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A164773 Numbers n with property that average digit of n^2 is s=7. 7
1667, 2167, 2383, 2387, 2437, 2563, 2567, 2617, 2626, 2824, 2828, 2963, 3143, 3157, 17313, 19437, 19917, 21417, 21633, 22083, 22113, 22293, 23214, 23622, 23664, 23874, 23937, 24207, 24228, 24267, 24417, 24474, 25824, 25836, 25863, 26067 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..925

EXAMPLE

1667^2=2778889 and (2+7+7+8+8+8+9)/7=7

17313^2=299739969 and (2+9+9+7+3+9+9+6+9)/9=7.

MATHEMATICA

Select[Range[30000], Mean[IntegerDigits[#^2]]==7&] (* Harvey P. Dale, Feb 22 2013 *)

PROG

(PARI) dsum(n)={my(s=0); while(n>9, s+=n%10; n\=10); s+n}; for(n=1, 1e6, if(dsum(n^2)/#Str(n^2)==7, print1(n", ")))

CROSSREFS

A164770 (s=2), A164771 (s=1), A164772 (s=8).

Sequence in context: A068744 A280404 A054811 * A321001 A054812 A020392

Adjacent sequences:  A164770 A164771 A164772 * A164774 A164775 A164776

KEYWORD

nonn,base,easy

AUTHOR

Zak Seidov, Aug 26 2009

EXTENSIONS

Program by Charles R Greathouse IV, Nov 01 2009

STATUS

approved

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Last modified March 3 02:41 EST 2021. Contains 341756 sequences. (Running on oeis4.)