cp's OEIS Frontend

A264971 If A262686(n) = 0, a(n) = 1, otherwise a(n) = 1 + a(A262686(n)), where A262686(n) = largest number k such that k - d(k) = n, or 0 if no such number exists, and d(n) = the number of divisors of n (A000005).

%I A264971 #8 Dec 03 2015 04:36:17
%S A264971 13,3,12,3,2,2,11,1,1,4,3,3,10,1,2,6,2,5,9,1,1,4,8,3,1,1,3,2,1,2,7,7,
%T A264971 2,1,6,6,1,1,7,5,1,2,5,1,2,4,4,3,6,1,1,2,1,3,3,1,1,2,2,5,5,4,4,1,1,3,
%U A264971 1,1,1,2,3,4,4,3,1,1,3,2,5,1,2,2,4,4,3,1,3,3,1,5,4,2,2,4,3,6,2,5,1,3,1
%N A264971 If A262686(n) = 0, a(n) = 1, otherwise a(n) = 1 + a(A262686(n)), where A262686(n) = largest number k such that k - d(k) = n, or 0 if no such number exists, and d(n) = the number of divisors of n (A000005).
%C A264971 See comments at A264970.
%H A264971 Antti Karttunen, <a href="/A264971/b264971.txt">Table of n, a(n) for n = 0..10000</a>
%F A264971 If A060990(n) = 0, a(n) = 1, otherwise a(n) = 1 + a(A262686(n)).
%F A264971 Other identities. For all n >= 0:
%F A264971 a(n) = 1 + A264970(n).
%o A264971 (Scheme, with memoization-macro definec)
%o A264971 (definec (A264971 n) (cond ((A262686 n) => (lambda (lad) (if (zero? lad) 1 (+ 1 (A264971 lad)))))))
%Y A264971 Cf. A000005, A049820, A060990, A262686.
%Y A264971 One more than A264970.
%Y A264971 Number of significant terms on row n of A263271.
%K A264971 nonn
%O A264971 0,1
%A A264971 _Antti Karttunen_, Nov 29 2015