1,1

Or, numbers m such A121937(m)=5. Cf. A121937 a(n) = least m >= 2 such that (n mod m) > (n+2 mod m).

a(n) = 3*(sin((n*Pi)/2)- cos((n*Pi)/2)+5*n-3)

9 is here because least k such that (9 mod k) > (11 mod k) is 5;

24 is here because least k such that (24 mod k) > (26 mod k) is 5.

Table[15*n-9-3*Cos[(n*Pi)/2]+3*Sin[(n*Pi)/2], {n, 60}]

Cf. A121937.

Adjacent sequences: A121450 A121451 A121452 this_sequence A121454 A121455 A121456

Sequence in context: A101058 A102217 A124065 this_sequence A003343 A047720 A063066

nonn

Zak Seidov (zakseidov(AT)yahoo.com), Sep 07 2006