A222293 Conjectured total number of times that k+n appears in the Collatz (3x+1) sequence of k for k = 1, 2, 3,...

37, 30, 34, 30, 31, 29, 28, 38, 42, 32, 40, 40, 49, 30, 40, 40, 54, 45, 46, 40, 49, 44, 41, 48, 47, 54, 48, 41, 50, 44, 54, 45, 49, 60, 53, 47, 54, 50, 56, 44, 48, 50, 54, 47, 54, 38, 56, 47, 60, 48, 63, 48, 47, 45, 56, 53, 49, 49, 62, 52, 50, 54, 53, 52, 49, 46

Offset: 1

Author

T. D. Noe, Feb 22 2013

Keywords

• nonn

Examples

			a(1) = 37 because k+1 occurs in the Collatz sequence of k for the 37 values in A070993.
		

Links

• T. D. Noe, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A070993, A221213 (k-n).

Programs

Mathematica

Collatz[n_] := NestWhileList[If[EvenQ[#], #/2, 3 # + 1] &, n, # > 1 &]; nn = 75; t = Table[0, {nn}]; lastChange = 10; k = 0; While[k < 2*lastChange, k++; c = Collatz[k]; d = Intersection[Range[nn], c - k]; If[Length[d] > 0, lastChange = k; t[[d]]++]]