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A270807
Trajectory of 1 under the map n -> n + n/gpf(n) + 1 (see A269304).
5
1, 3, 5, 7, 9, 13, 15, 19, 21, 25, 31, 33, 37, 39, 43, 45, 55, 61, 63, 73, 75, 91, 99, 109, 111, 115, 121, 133, 141, 145, 151, 153, 163, 165, 181, 183, 187, 199, 201, 205, 211, 213, 217, 225, 271, 273, 295, 301, 309, 313, 315, 361, 381, 385, 421, 423, 433, 435, 451, 463, 465
OFFSET
1,2
COMMENTS
Cody M. Haderlie (see A269304) conjectures that the trajectory of any initial value will eventually merge with this sequence. The trajectory of 2, for example, begins 2, 4, 7, 9, 13, 15, 19, 21, 25, ... and from 7 on coincides with this sequence. See A271418.
PROG
(Python)
from __future__ import division
from sympy import primefactors
A270807_list, b = [], 1
for i in range(10000):
A270807_list.append(b)
b += b//(max(primefactors(b)+[1])) + 1 # Chai Wah Wu, Apr 06 2016
(PARI) gpf(n) = if (n==1, 1, vecmax(factor(n)[, 1]));
lista(nn) = {a = 1; for (n=1, nn, print1(a, ", "); a = a + a/gpf(a) + 1; ); } \\ Michel Marcus, Apr 06 2016
CROSSREFS
For first differences see A270808.
Sequence in context: A338129 A327573 A306069 * A157048 A190857 A003543
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Apr 05 2016
STATUS
approved