A253425 Lengths of runs of identical terms in A253415.

1, 1, 6, 11, 18, 12, 5, 22, 91, 143, 1, 93, 370, 182, 20, 20, 315, 332, 973, 157, 1223, 1807, 325, 4044, 7412, 11211, 4600, 2176, 14848, 4659, 3123, 10852, 1678, 20862, 3348

Offset

1,3

Links

Table of n, a(n) for n=1..35.

Mathematica

c[_] = 0; c[1] = j = 1; u = 2; s = 3; Most@ Tally[#][[All, -1]] &@ Reap[Do[d = Divisors[s]; k = 1; While[c[d[[k]]] > 0, k++]; Set[k, d[[k]]]; Set[c[k], i]; If[k == u, While[c[u] > 0, u++]]; Sow[u]; j = k; s += k, {i, 2, 2^12}]][[-1, -1]] (* Michael De Vlieger, Jan 23 2022 *)

Prog

(Haskell)
import Data.List (group)
a253425 n = a253425_list !! (n-1)
a253425_list = map length $ group a253415_list
(Python)
from itertools import islice
from sympy import divisors
def A253425_gen(): # generator of terms
    bset, l, m, s = {1}, 0, 2, 3
    while True:
        for d in divisors(s):
            if d not in bset:
                bset.add(d)
                if m in bset:
                    yield l
                    l = 1
                    while m in bset:
                        m += 1
                else:
                    l += 1
                s += d
                break
A253425_list = list(islice(A253425_gen(), 20)) # Chai Wah Wu, Jan 25 2022

Crossrefs

Cf. A253415, A095258.

Sequence in context: A271987 A184550 A109330 * A099225 A315555 A315556

Adjacent sequences: A253422 A253423 A253424 * A253426 A253427 A253428

Keyword

nonn,more

Author

Reinhard Zumkeller, Dec 31 2014

Extensions

a(14)-a(35) from Michael De Vlieger, Jan 23 2022

Status

approved