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A212190 Squares that are the sum of exactly three distinct powers of 2. 4
25, 49, 81, 100, 196, 289, 324, 400, 529, 784, 1089, 1156, 1296, 1600, 2116, 3136, 4225, 4356, 4624, 5184, 6400, 8464, 12544, 16641, 16900, 17424, 18496, 20736, 25600, 33856, 50176, 66049, 66564, 67600, 69696, 73984, 82944, 102400, 135424, 200704, 263169 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Squares with exactly three ones in their binary representation: A000120(a(n)) = 3;

squares in A014311;

a(n) = A212191(n)^2.

LINKS

Giovanni Resta, Table of n, a(n) for n = 1..10000 (first 1000 terms from Reinhard Zumkeller)

MATHEMATICA

Select[Range[1000]^2, DigitCount[#, 2, 1] == 3&] (* Jean-Fran├žois Alcover, Nov 07 2016 *)

PROG

(Haskell)

a212190 n = a212190_list !! (n-1)

a212190_list = filter ((== 1) . a010052) a014311_list

CROSSREFS

Cf. A010052, A212192.

Sequence in context: A067794 A068874 A018936 * A324871 A241836 A110484

Adjacent sequences:  A212187 A212188 A212189 * A212191 A212192 A212193

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, May 03 2012

STATUS

approved

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Last modified February 26 03:10 EST 2021. Contains 341619 sequences. (Running on oeis4.)