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 A316484 Squares whose arithmetic mean of digits is 4 (i.e., the sum of digits is 4 times the number of digits). 2
 4, 1681, 3364, 3481, 4624, 7225, 9025, 1054729, 1069156, 1073296, 1149184, 1168561, 1183744, 1227664, 1263376, 1288225, 1308736, 1329409, 1366561, 1517824, 1522756, 1545049, 1567504, 1585081, 1607824, 1630729, 1635841, 1677025, 1682209, 1705636, 1729225 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Each term's number of digits is in A056991 (Numbers with digital root 1, 4, 7, or 9). For every term k in A056991, this sequence contains at least one k-digit term. (See A316480.) LINKS Robert Israel, Table of n, a(n) for n = 1..10000 EXAMPLE 1027^2 + 1054729, a 7-digit number whose digit sum is 1+0+5+4+7+2+9 = 28 = 4*7, so 1054729 is a term. 10044^2 = 100881936, a 9-digit number whose digit sum is 1+0+0+8+8+1+9+3+6 = 36 = 4*9, so 100881936 is a term. MAPLE f:= proc(n) local L;   L:= convert(n^2, base, 10);   if convert(L, `+`)=4*nops(L) then n^2 fi end proc: map(f, [\$1..2000]); # Robert Israel, Jul 05 2018 MATHEMATICA Select[Range[1500]^2, Mean[IntegerDigits[#]] == 4 &] (* Giovanni Resta, Jul 05 2018 *) PROG (PARI) isok(n) = (n>0) && issquare(n) && (sumdigits(n) == 4*#digits(n)); \\ Michel Marcus, Jul 05 2018 CROSSREFS Cf. A056991, A069711, A316480. Sequence in context: A265661 A280793 A160225 * A278794 A141090 A307580 Adjacent sequences:  A316481 A316482 A316483 * A316485 A316486 A316487 KEYWORD nonn,base AUTHOR Jon E. Schoenfield, Jul 04 2018 STATUS approved

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Last modified November 23 21:51 EST 2020. Contains 338603 sequences. (Running on oeis4.)