The OEIS is supported by the many generous donors to the OEIS Foundation.

 Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 60th year, we have over 367,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”). Other ways to Give
 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A110084 Numbers n with even length such that sigma(n)=d_1^d_2*d_3^d_4 *...*d_(k-1)^d_k where d_1 d_2 ... d_k is the decimal expansion of n. 5
 146710, 334552, 12931485, 15734393, 16839254, 20499191, 28661422, 38722820, 43681330, 44463034, 45509442, 55188392, 55938216, 92505149, 1054662422, 1060804965, 1068721252, 1094834272, 1167528360, 1341465139, 1436725284, 1452198772, 1452847236, 1540709585, 1594291529, 1596602643, 1672853710 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Max Alekseyev, Table of n, a(n) for n = 1..99 EXAMPLE 45509442 is in the sequence because sigma(55938216)=5^5*9^3*8^2*1^6. MATHEMATICA Do[h = IntegerDigits[n]; k = Length[h]; If[EvenQ[k] && Select[ Range[k/2], h[[2#-1]] == 0 &] == {} && DivisorSigma[1, n]== Product[h[[2j-1]]^h[[2j]], {j, k/2}], Print[n]], {n, 10^8}] CROSSREFS Cf. A112009, A112010, A112011. Sequence in context: A237297 A204527 A345753 * A224587 A004670 A111044 Adjacent sequences: A110081 A110082 A110083 * A110085 A110086 A110087 KEYWORD base,nonn AUTHOR Farideh Firoozbakht, Aug 26 2005 EXTENSIONS Terms a(14) onward from Max Alekseyev, Oct 16 2012 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 December 3 05:03 EST 2023. Contains 367531 sequences. (Running on oeis4.)