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

0,5

Comments

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

Links

Table of n, a(n) for n=0..104.

Example

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.

Sequence in context: A224963 A073810 A055255 * A317990 A106030 A104888

Adjacent sequences: A057765 A057766 A057767 * A057769 A057770 A057771

Keyword

easy,fini,nonn

Author

Naohiro Nomoto, Nov 01 2000

Status

approved