A057768 From Goldbach problem: number of decompositions of 2n-1 into sum of a prime lucky number(from A031157) and a twin even-lucky-number(from A045955, A045956).

0, 0, 1, 1, 2, 1, 2, 2, 2, 2, 1, 2, 3, 1, 1, 1, 2, 2, 2, 2, 3, 3, 2, 4, 5, 2, 3, 4, 4, 2, 2, 2, 3, 2, 1, 3, 4, 3, 4, 4, 4, 4, 5, 3, 3, 3, 2, 2, 2, 2, 4, 2, 3, 3, 3, 3, 3, 3, 3, 2, 4, 3, 2, 2, 4, 4, 4, 3, 4, 3, 3, 4, 5, 4, 3, 3, 4, 3, 3, 1, 5, 4, 2, 3, 6, 4, 5, 5, 4, 4, 6, 4, 5, 3, 1, 2, 3, 4, 5, 4, 3, 5, 6, 3, 3

Offset: 0

Author

Naohiro Nomoto, Nov 01 2000

Keywords

• easy
• fini
• nonn

Comments

Conjecture: this sequence is always positive (with n>2).

Examples

			1 and 3 are not the sum of a prime lucky number and a twin even-lucky-number, so a(1) = a(2) = 0; 5=3+2 (one way, so a(3)=1); 7=3+4 (so a(4)=1); 9=3+6=7+2 (so a(5)=2); etc.
		

Crossrefs

Cf. A045954, A045955, A045956, A031157, A000959, A002375, A045917.