A281827 Least number k such that k is the sum of two primes in exactly n ways, where both primes are of the form x^2 + y^2, or -1 if no such k exists.

0, 4, 34, 58, 102, 114, 186, 282, 246, 210, 354, 390, 330, 426, 462, 666, 906, 774, 750, 690, 630, 870, 1026, 990, 1122, 1134, 1110, 1050, 1170, 1554, 1914, 1290, 1530, 1650, 1470, 1770, 1830, 2142, 1710, 2070, 2874, 1950, 2250, 1890, 2838, 2370, 2550, 2490, 2430, 3354, 2670, 3726

Offset

0,2

Links

Table of n, a(n) for n=0..51.

Example

a(2) = 34 because 34 = 5 + 29 = 17 + 17; 5, 17, 29 are primes of the form x^2 + y^2 and 34 is the least number with this property.

Crossrefs

Cf. A001172, A002313.

Sequence in context: A220168 A227397 A365537 * A284812 A053902 A054464

Adjacent sequences: A281824 A281825 A281826 * A281828 A281829 A281830

Keyword

nonn

Author

Altug Alkan, Jan 31 2017

Status

approved