A350172 Start from 1st prime 2, and write it twice, then add 3 to get 5 and write it 3 times, then add 5 to get 10 and write it 5 times, and so on.

2, 2, 5, 5, 5, 10, 10, 10, 10, 10, 17, 17, 17, 17, 17, 17, 17, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 77, 77, 77, 77, 77, 77, 77, 77

Offset

1,1

References

J.-P. Delahaye, Des suites fractales d’entiers, Pour la Science, No. 531 January 2022. Sequence e) p. 82.

Links

Table of n, a(n) for n=1..66.

Mathematica

nxt[{p_, t_}]:=Module[{n=NextPrime[p]}, {n, PadRight[{}, n, t+n]}]; Join[{2}, NestList[nxt, {2, 2}, 10][[;; , 2]]]//Flatten (* Harvey P. Dale, Jun 05 2023 *)

Prog

(Python)
from sympy import nextprime
from itertools import islice, repeat
def primes(p=2):
    while True: yield p; p = nextprime(p)
def agen():
    primesum = 0
    for p in primes():
        primesum += p
        yield from repeat(primesum, p)
print(list(islice(agen(), 66))) # Michael S. Branicky, Dec 18 2021

Crossrefs

Cf. A007504.

Sequence in context: A063960 A295514 A025510 * A356387 A172417 A158106

Adjacent sequences: A350169 A350170 A350171 * A350173 A350174 A350175

Keyword

nonn

Author

Michel Marcus, Dec 18 2021

Extensions

a(19) and beyond from Michael S. Branicky, Dec 18 2021

Status

approved