A277495 a(1) = 1; a(n) = n if a(n-1) = 1; otherwise, a(n) = digit sum (n written in base a(n-1)).

1, 2, 2, 1, 5, 2, 3, 4, 3, 2, 3, 2, 3, 4, 6, 6, 7, 6, 4, 2, 3, 4, 5, 8, 4, 5, 3, 2, 4, 6, 6, 7, 9, 10, 8, 8, 9, 6, 4, 4, 5, 6, 3, 6, 5, 6, 7, 12, 5, 2, 4, 4, 5, 6, 5, 4, 6, 8, 10, 6, 6, 7, 3, 4, 2, 2, 3, 6, 9, 14, 6, 2, 3

Offset

1,2

Links

Table of n, a(n) for n=1..73.

Example

a(15-1) = 4; 15 in base 4 is 33; 3+3 = 6, so a(15) = 6.

Mathematica

$RecursionLimit=100
a[1]=1;
a[n_]:=If[a[n-1]!=1, Total[IntegerDigits[n, a[n-1]]], n]
Array[a, 100]

Prog

(PARI) lista(nn) = {print1(a = 1, ", "); for (n=2, nn, if (a==1, a = n, a = vecsum(digits(n, a)); ); print1(a, ", "); ); } \\ Michel Marcus, Oct 21 2016

Crossrefs

Sequence in context: A203953 A326933 A123398 * A188945 A281261 A102849

Adjacent sequences: A277492 A277493 A277494 * A277496 A277497 A277498

Keyword

nonn,base

Author

Cody M. Haderlie, Oct 17 2016

Status

approved