The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A334392 Numbers m such that the LCM of their palindromic divisors is neither 1 nor m. 1
 16, 25, 26, 27, 32, 34, 38, 39, 46, 48, 49, 50, 51, 52, 54, 57, 58, 62, 64, 65, 68, 69, 74, 75, 76, 78, 80, 81, 82, 85, 86, 87, 91, 92, 93, 94, 95, 96, 98, 100, 102, 104, 106, 108, 112, 114, 115, 116, 117, 118, 119, 122, 123, 124, 125, 128, 129, 130, 133, 134 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS A334139, A334391 and this sequence form a partition of the set of positive integers N* (A000027). The integers {2^k, k >= 4, 2^k non-palindrome} form a subsequence whose first few terms are : 16, 32, 64, 128, ... LINKS Table of n, a(n) for n=1..60. Wikipedia, Partition of a set EXAMPLE 50 has 3 palindromic divisors {1, 2, 5} then A087999(50) = 10 and 50 is a term. MATHEMATICA Select[Range[125], !MemberQ[{1, #}, LCM @@ Select[Divisors[#], PalindromeQ]] &] (* Amiram Eldar, May 05 2020 *) PROG (PARI) ispal(x) = my(d=digits(x)); d == Vecrev(d); isok(m) = my(d=divisors(m), lcmpd = lcm(select(x->ispal(x), d))); (lcmpd != 1) && (lcmpd != m); \\ Michel Marcus, May 05 2020 CROSSREFS Cf. A087990, A087999. Cf. A334391 [LCM(palindromic divisors of m) = 1], A334139 [LCM(palindromic divisors of m) = m], this sequence [LCM(palindromic divisors of m) != 1 and != m]. Sequence in context: A170985 A202335 A071524 * A227651 A348320 A095409 Adjacent sequences: A334389 A334390 A334391 * A334393 A334394 A334395 KEYWORD nonn,base AUTHOR Bernard Schott, May 04 2020 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified May 30 03:30 EDT 2024. Contains 372957 sequences. (Running on oeis4.)