OFFSET
1,9
COMMENTS
LINKS
Robert G. Wilson v, Table of n, a(n) for n = 1..100000
EXAMPLE
a(9) = 2 because there are 2 steps in going from 9 to 0 in A121559: 9 mod 7 = 2 and 2 mod 2 = 0.
MATHEMATICA
LrgstPrm[n_] := Block[{k = n}, While[ !PrimeQ@ k, k-- ]; k]; f[n_] := Block[{c = 0, d = n}, While[d > 1, d = d - LrgstPrm@d; c++ ]; c]; Array[f, 105] (* Robert G. Wilson v, Feb 29 2008 *)
PROG
(Python)
from sympy import prevprime
def a(n): return 0 if n == 0 or n == 1 else 1 + a(n - prevprime(n+1))
print([a(n) for n in range(1, 106)]) # Michael S. Branicky, Jul 26 2022
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Kerry Mitchell, Aug 07 2006
STATUS
approved