OFFSET
1,2
LINKS
Michael De Vlieger, Table of n, a(n) for n = 1..12386 (rows 1 <= n <= 1000, flattened)
John Machacek, Egyptian Fractions and Prime Power Divisors, Journal of Integer Sequences, Vol. 21 (2018), Article 18.3.7.
EXAMPLE
Triangle begins:
1;
2, 1;
3, 2, 1;
4, 2, 1;
5, 4, 2, 1;
6, 3, 2, 1;
7, 6, 3, 2, 1;
8, 4, 2, 1;
9, 6, 3, 2, 1;
10, 5, 4, 2, 1;
MAPLE
j := 1:a[1] := 1:for i from 2 to 50 do n := i:j := j+1:a[j] := n:while(n>1) do if isprime(n) then r := n-1: else r := n-n/ifactors(n)[2][1][1]; fi; n := r:j := j+1:a[j] := n: od:od:seq(a[k], k=1..j);
MATHEMATICA
Array[If[# == 1, {1}, NestWhileList[If[PrimeQ@ #, # - 1, # - #/FactorInteger[#][[1, 1]] ] &, #, # > 1 &]] &, 20] // Flatten (* Michael De Vlieger, Apr 15 2020 *)
CROSSREFS
KEYWORD
nonn,tabf
AUTHOR
Amarnath Murthy, Aug 19 2002
EXTENSIONS
More terms from Sascha Kurz, Aug 23 2002
Offset corrected from 0 to 1 by Antti Karttunen, Aug 23 2017
STATUS
approved