A339047 a(n) gives the multiplicity for A154777(n) representable as x^2 + 2*y^2 with positive integers x and y, for n >= 1.

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 1, 2, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 3, 2, 1, 2, 1, 2, 1, 1, 2, 2, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 2, 1, 1, 1, 3, 1, 1, 2, 1, 1, 2, 1, 1, 1, 3

Offset

1,11

Links

Table of n, a(n) for n=1..75.

Formula

a(n) gives the number of occurrences of A154777(n) = x^2 + 2*y^2 with positive integers x and y. This is obtained from triangle A338432.

Example

See A338432 for examples.
The pairs [A154777(n), a(n)] begin:
[3, 1], [6, 1], [9, 1], [11, 1], [12, 1], [17, 1], [18, 1], [19, 1], [22, 1], [24, 1], [27, 2], [33, 2], [34, 1], [36, 1], [38, 1], [41, 1], [43, 1], [44, 1], [48, 1], [51, 2], [54, 2], [57, 2], [59, 1], [66, 2], [67, 1], [68, 1], [72, 1], [73, 1], [75, 1], [76, 1], [81, 2], [82, 1], [83, 1], [86, 1], [88, 1], [89, 1], [96, 1], [97, 1], [99, 3], ...

Crossrefs

Cf. A154777, A338432.

Sequence in context: A102681 A274013 A172086 * A347735 A204014 A339184

Adjacent sequences: A339044 A339045 A339046 * A339048 A339049 A339050

Keyword

nonn,easy

Author

Wolfdieter Lang, Dec 09 2020

Status

approved