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!)
 A125834 Numbers that have exactly 15 representations as a product of two palindromes. 2
 4888884, 8896888, 13345332, 74732526, 100999899, 140732592, 179555376, 269130862, 295777482, 444888444, 734059326, 880968088, 978745768, 1032039008, 1183109928, 1321452132, 1399939992, 1548058512, 1614785172, 1886140256 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Table of n, a(n) for n=1..20. EXAMPLE 4888884 is in the sequence since 4888884 = 1*4888884 = 2*2444442 = 4*1222221 = 11*444444 = 22*222222 = 44*111111 = 111*44044 = 121*40404 = 222*22022 = 242*20202 = 444*11011 = 484*10101 = 1001*4884 = 1221*4004 = 2002*2442. MATHEMATICA f[n_]:=f[n]=Length[Select[Divisors[n], #<=n^(1/2)&&FromDigits[ Reverse[IntegerDigits[ # ]]]==#&&FromDigits[Reverse[IntegerDigits [n/# ]]]==n/#&]]; Do[If[f[n]==15, Print[n]], {n, 125000000}] CROSSREFS Cf. A002113, A116993, A125832, A125833, A125835. Sequence in context: A361075 A147580 A043662 * A178293 A218108 A089234 Adjacent sequences: A125831 A125832 A125833 * A125835 A125836 A125837 KEYWORD base,nonn AUTHOR Farideh Firoozbakht, Dec 11 2006 EXTENSIONS a(6)-a(20) from Donovan Johnson, Aug 05 2009 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 June 17 02:48 EDT 2024. Contains 373432 sequences. (Running on oeis4.)