# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a292269 Showing 1-1 of 1 %I A292269 #10 Oct 04 2017 14:05:03 %S A292269 1,1,1,4,1,3,1,4,9,5,1,3,1,7,5,4,1,3,1,4,7,11,1,3,25,13,9,4,1,3,1,4, %T A292269 11,17,7,3,1,19,13,4,1,3,1,4,5,23,1,3,49,5,17,4,1,3,11,4,19,29,1,3,1, %U A292269 31,7,4,13,3,1,4,23,5,1,3,1,37,5,4,11,3,1,4,9,41,1,3,17,43,29,4,1,3,13,4,31,47,19,3,1,7,9,4,1,3,1,4,5 %N A292269 If n is 1 or a prime, then a(n) = 1, otherwise a(n) = the third smallest divisor of n. %H A292269 Antti Karttunen, Table of n, a(n) for n = 1..10000 %F A292269 If A020639(n)^2 divides n [when n is in A283050] and either A119288(n) = 1 or A020639(n)^2 < A119288(n), then a(n) = A020639(n)^2, otherwise a(n) = A119288(n). %o A292269 (PARI) A292269(n) = { my(ds=divisors(n)); if(numdiv(n)<3,1,ds[3]); } %o A292269 (Scheme) (define (A292269 n) (let ((x (A000290 (A020639 n))) (y (A119288 n))) (if (and (zero? (modulo n x)) (or (= 1 y) (< x y))) x y))) %Y A292269 Cf. A000005, A020639, A119288, A171783, A283050, A284255, A284260. %Y A292269 Cf. A008578 (positions of ones). %K A292269 nonn %O A292269 1,4 %A A292269 _Antti Karttunen_, Oct 04 2017 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE