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A124981 Odd numbers that are not the sum of 2 squares. 0
3, 7, 11, 15, 19, 21, 23, 27, 31, 33, 35, 39, 43, 47, 51, 55, 57, 59, 63, 67, 69, 71, 75, 77, 79, 83, 87, 91, 93, 95, 99, 103, 105, 107, 111, 115, 119, 123, 127, 129, 131, 133, 135, 139, 141, 143, 147, 151, 155, 159, 161, 163, 165, 167, 171, 175, 177, 179, 183, 187 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

FORMULA

Equals A022544 INTERSECT A005408. - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Nov 29 2006

EXAMPLE

13 is not in the list because it can be written as 3^2+2^2.

PROG

(PARI) isA022544(n)={ local(cnt=0, y2) ; for(x=0, floor(sqrt(n)), y2=n-x^2 ; if( y2>=x^2 && issquare(y2), return(0) ; ) ; ) ; return(1) ; } isA124981(n)={ return( (n%2) && isA022544(n)) ; } { for(n=1, 200, if( isA124981(n), print1(n, ", ") ; ) ; ) ; } - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Nov 29 2006

CROSSREFS

Cf. A022544.

Sequence in context: A168285 A079710 A145832 * A059554 A184422 A189534

Adjacent sequences:  A124978 A124979 A124980 * A124982 A124983 A124984

KEYWORD

nonn

AUTHOR

Artur Jasinski (grafix(AT)csl.pl), Nov 15 2006

EXTENSIONS

Corrected and extended by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Nov 29 2006

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Last modified February 17 21:13 EST 2012. Contains 206085 sequences.