A345983 Partial sums of A344005.

1, 2, 4, 7, 11, 13, 19, 26, 34, 38, 48, 51, 63, 69, 74, 89, 105, 113, 131, 135, 141, 151, 173, 181, 205, 217, 243, 250, 278, 283, 313, 344, 355, 371, 385, 393, 429, 447, 459, 474, 514, 520, 562, 573, 582, 604, 650, 665, 713, 737, 754, 766, 818, 844, 854, 861, 879, 907, 965, 980, 1040, 1070

Offset

1,2

Links

N. J. A. Sloane, Table of n, a(n) for n = 1..10000

N. J. A. Sloane, Table of n, a(n) for n = 1..100000

Mathematica

spm[n_]:=Module[{m=1}, While[!Divisible[m(m+1), n], m++]; m]; Accumulate[ Array[ spm, 100]] (* Harvey P. Dale, Dec 04 2022 *)

Prog

(Python 3.8+)
from itertools import combinations, count, islice
from math import prod
from sympy import factorint
from sympy.ntheory.modular import crt
def A345983_gen(): # generator of terms
    c = 1
    for n in count(2):
        yield c
        plist = tuple(p**q for p, q in factorint(n).items())
        c += n-1 if len(plist) == 1 else int(min(min(crt((m, n//m), (0, -1))[0], crt((n//m, m), (0, -1))[0]) for m in (prod(d) for l in range(1, len(plist)//2+1) for d in combinations(plist, l))))
A345983_list = list(islice(A345983_gen(), 25)) # Chai Wah Wu, Jun 01 2022

Crossrefs

Cf. A011772, A344005, A345984.

Sequence in context: A327572 A370905 A362946 * A177754 A086795 A064690

Adjacent sequences: A345980 A345981 A345982 * A345984 A345985 A345986

Keyword

nonn

Author

N. J. A. Sloane, Jul 09 2021

Status

approved