A369384 The smallest number k that can be partitioned in n ways as the sum of two numbers from A020487.

1, 2, 29, 181, 442, 425, 850, 1300, 2600, 3250, 5525, 11050, 17425, 16900, 44100, 18850, 72250, 44200, 122525, 75400, 55250, 110500, 237250, 188500, 266500, 397800, 375700, 377000, 187850, 221000, 469625, 718250, 640900, 1105000, 1812200, 2340900, 751400, 3591250

Offset: 0

Author

Marius A. Burtea, Jan 25 2024

Keywords

• nonn

Examples

			a(0) = 1 because 1 cannot be written as the sum of two terms in A020487.
2 = 1 + 1 = A020487(1) + A020487(1), so a(1) = 2.
The numbers 3, 4, ..., 28 can be written as the sum of two terms in A020487 in at most one way and 29 = 4 + 25 = A020487(2) + A020487(6) and 29 = 9 + 20 = A020487(3) + A020487(5), so a(2) = 29.
		

Links

• Michael S. Branicky, Table of n, a(n) for n = 0..106

Crossrefs

Cf. A000203, A001157, A020487.

Programs

Magma

ant:=func; b:=[n: n in [1..700000] |ant(n)]; a:=[]; for n in [0..30] do k:=1; while #RestrictedPartitions(k,2,Set(b)) ne n do k:=k+1; end while; Append(~a,k); end for; a;

Extensions

a(16) corrected and more terms from Michael S. Branicky, Feb 24 2024