A262891 a(n) = A060990(A259934(n)); branching degree of node n in the infinite trunk of the tree generated by edge-relation A049820(child) = parent.

2, 1, 3, 1, 1, 4, 1, 2, 1, 3, 1, 2, 2, 4, 2, 1, 1, 3, 1, 2, 3, 1, 2, 3, 2, 2, 3, 4, 2, 2, 1, 1, 1, 2, 3, 2, 1, 1, 2, 1, 2, 2, 3, 3, 1, 1, 3, 2, 2, 1, 1, 1, 4, 1, 1, 1, 2, 2, 1, 2, 1, 2, 1, 2, 2, 1, 2, 2, 1, 3, 2, 1, 1, 1, 1, 1, 1, 3, 2, 2, 1, 2, 2, 1, 1, 2, 2, 2, 2, 2, 1, 1, 2, 1, 2, 2, 1, 3, 2, 2, 4, 2, 2, 2, 3, 2, 2, 3, 2, 1, 2, 2, 1, 3, 2, 2, 3, 1, 2, 3, 2, 2, 1

Offset: 0

Author

Antti Karttunen, Oct 04 2015

Keywords

• nonn

Links

• Antti Karttunen, Table of n, a(n) for n = 0..10341

Crossrefs

Cf. A049820, A060990, A259934.

Positions of ones: A262892.

Programs

Mathematica

nMax = 122; seq0 = {0}; seq = {1}; K = 1; While[seq != seq0, Print["K = ", K]; NN = K*nMax; Clear[A, B, S]; S[] = 0; For[n = NN + 1, n <= 2*NN, n++, k = n - DivisorSigma[0, n]; If[k <= NN, S[k] = S[k] + 1; B[k] = n]]; For[n = NN, n >= 3, n--, If[S[n] >= 1, k = n - DivisorSigma[0, n]; S[k] = S[k] + 1; B[k] = n]]; A[0] = 0; A[1] = 2; For[n = 2, True, n++, b = B[A[n - 1]]; If[b > NN || S[b] > 1, Break[]]; A[n] = b]; Clear[a0]; a0[] = 0; Do[n = x - DivisorSigma[0, x]; a0[n]++, {x, 1, NN}]; a[n_] := a0[A[n]]; seq0 = seq; seq = Table[a[n], {n, 0, nMax}]; K = 2K]; A262891 = seq (* Jean-François Alcover, Nov 16 2016, after Robert Israel for A259934 *)

Scheme

(define (A262891 n) (A060990 (A259934 n)))

Formula

a(n) = A060990(A259934(n)).