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Search: id:A118886
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A118886 Numbers expressible as i^2+i*j+j^2, 0<=i<=j, in 2 or more ways. +0
2
49, 91, 133, 147, 169, 196, 217, 247, 259, 273, 301, 343, 361, 364, 399, 403, 427, 441, 469, 481, 507, 511, 532, 553, 559, 588, 589, 637, 651, 676, 679, 703, 721, 741, 763, 777, 784, 793, 817, 819, 868, 871, 889, 903, 931, 949, 961, 973, 988, 1027, 1029, 1036 (list; graph; listen)
OFFSET

1,1

COMMENT

Squares of distances between two points in the triangular lattice in two or more nontrivially different ways.

FORMULA

Numbers whose prime factorization contains at least two (not necessarily distinct) primes congruent to 1 mod 6, and any prime factor congruent to 2 mod 3 has even multiplicity. Products of two elements of A024606.

CROSSREFS

Cf. A024606, A118882.

Sequence in context: A006832 A093894 A090825 this_sequence A108164 A020158 A084632

Adjacent sequences: A118883 A118884 A118885 this_sequence A118887 A118888 A118889

KEYWORD

nonn

AUTHOR

Frank Adams-Watters (FrankTAW(AT)Netscape.net), May 03 2006

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Last modified November 18 20:14 EST 2008. Contains 147244 sequences.


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