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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A137179 a(n) = the smallest positive integer m such that d(m) + d(m+1) = n, where d(m) is the number of positive divisors of m. (a(n) is the smallest m where A092405(m) = n.) 1
 1, 2, 3, 5, 8, 11, 15, 20, 24, 39, 35, 59, 80, 84, 195, 167, 120, 119, 224, 239, 399, 335, 440, 359, 360, 480, 1520, 539, 899, 719, 1224, 720, 840, 1079, 3135, 1259, 5183, 1260, 2400, 2160, 1680, 1679, 9408, 2880, 7056, 2639, 3024, 2520, 6240, 2519, 7055, 6929 (list; graph; refs; listen; history; text; internal format)
 OFFSET 3,2 LINKS Robert Israel, Table of n, a(n) for n = 3..250 MAPLE N:= 100: # for a(3)..a(N) V:= Array(3..N): count:= 0: dp:= 1: for m from 1 while count < N-2 do d:= dp; dp:= numtheory:-tau(m+1); v:= d+dp; if v <= N and V[v] = 0 then V[v]:= m; count:= count+1; fi od: convert(V, list); # Robert Israel, Mar 31 2021 MATHEMATICA a = {}; For[n = 3, n < 60, n++, i = 1; While[ ! DivisorSigma[0, i] + DivisorSigma[0, i + 1] == n, i++ ]; AppendTo[a, i]]; a (* Stefan Steinerberger, May 18 2008 *) CROSSREFS Cf. A092405. Sequence in context: A131073 A062485 A175143 * A356549 A096777 A125811 Adjacent sequences: A137176 A137177 A137178 * A137180 A137181 A137182 KEYWORD nonn AUTHOR Leroy Quet, May 11 2008 EXTENSIONS More terms from Stefan Steinerberger, May 18 2008 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 8 00:26 EDT 2023. Contains 363157 sequences. (Running on oeis4.)