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A004439
Numbers that are not the sum of 2 distinct nonzero squares.
4
1, 2, 3, 4, 6, 7, 8, 9, 11, 12, 14, 15, 16, 18, 19, 21, 22, 23, 24, 27, 28, 30, 31, 32, 33, 35, 36, 38, 39, 42, 43, 44, 46, 47, 48, 49, 51, 54, 55, 56, 57, 59, 60, 62, 63, 64, 66, 67, 69, 70, 71, 72, 75, 76, 77, 78, 79
OFFSET
1,2
LINKS
PROG
(PARI) is(n)=if(n<5, return(1)); my(f=factor(n)%4); if(vecmin(f[, 1])>1, return(1)); for(i=1, #f[, 1], if(f[i, 1]==3 && f[i, 2]%2, return(1))); 0 \\ Charles R Greathouse IV, Jun 18 2013
CROSSREFS
Complement of A004431.
Sequence in context: A188010 A350349 A008320 * A050126 A013939 A343109
KEYWORD
nonn
STATUS
approved