A226557 a(n) = |A020497(n) - prime(n+4) + 10|.

0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 2, 4, 2, 2, 0, 2, 4, 12, 12, 4, 6, 4, 8, 2, 6, 6, 4, 2, 0, 0, 6, 2, 4, 2, 8, 0, 2, 4, 2, 4, 8, 10, 6, 6

Offset: 1

Author

Vladimir Shevelev, Jun 10 2013

Keywords

• nonn

Comments

Approximation of A020497(n) by function of the form prime(n+k) - c, where k,c are constants. The choice k=4 is stipulated by removing 2 and 5 from the considered prime constellations and 11 is chosen as the first prime (for n=1), since the second constellation {11,13} should be a twin pair. The choice c=10 corresponds to a(0) = 0.

a(n) = 0 for n=1,2,3,4,5,7,8,9,10,11,12,13,14,15,16,22,36,37,43,...

Crossrefs

Cf. A020497.