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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A336803 Numbers k such that A230319(k) - A230319(k-1) = 2. 1
 3, 6, 9, 12, 15, 19, 22, 26, 30, 34, 38, 43, 47, 51, 56, 60, 65, 70, 75, 79, 84, 89, 94, 99, 104, 110, 115, 120, 125, 130, 136, 141, 147, 152, 158, 163, 169, 174, 180, 185, 191, 197, 202, 208, 214, 220, 225, 231, 237, 243, 249, 255, 261, 267, 273, 279, 285, 291 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Sánchez Garza and Treviño proved the counting function for this sequence is asymptotic to x/log x. See link. LINKS M. Sánchez Garza and E. Treviño, On a sequence related to the factoradic representation of an integer, Journal of Integer Sequences Vol. 24 (2021), Article 21.8.5. EXAMPLE 3 is a term because A230319(3) - A230319(2) = 2. MATHEMATICA j[r_] := j[r] = Module[{k = 1}, While[k! <= k^(r - 1), k++]; k]; jPrimes = {}; Do[If[j[r + 1] - j[r] == 2, AppendTo[jPrimes, r], 0], {r, 1, 2500}] PROG (PARI) f(n) = my(k=1); while (k^n >= k!, k++); k; \\ A230319 isok(n) = f(n) - f(n-1) == 2; \\ Michel Marcus, Jan 27 2021 CROSSREFS Cf. A230319. Sequence in context: A083354 A156242 A060293 * A220657 A194273 A123581 Adjacent sequences: A336800 A336801 A336802 * A336804 A336805 A336806 KEYWORD nonn AUTHOR Enrique Treviño, Jan 27 2021 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 March 30 06:16 EDT 2023. Contains 361606 sequences. (Running on oeis4.)