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A350867
Non-palindromic numbers k for which d(k) = d(R(k)), where R(k) is the reversal of k and d(k) is the number of divisors of k.
2
13, 15, 17, 24, 26, 31, 37, 39, 42, 51, 58, 62, 71, 73, 79, 85, 93, 97, 107, 113, 115, 117, 122, 123, 129, 143, 149, 155, 157, 158, 159, 165, 167, 169, 177, 178, 179, 183, 185, 187, 199, 203, 205, 221, 226, 246, 264, 265, 285, 286, 288, 294, 302, 311, 314, 319
OFFSET
1,1
LINKS
EXAMPLE
264 and 462 are non-palindromic and also d(264) = 16 = d(462), and so both are members.
PROG
(PARI) isok(k) = my(R = fromdigits(Vecrev(digits(k)))); R != k && numdiv(R) == numdiv(k);
(Python)
from sympy import divisor_count as d
def ok(k): Rk = int(str(k)[::-1]); return Rk != k and d(k) == d(Rk)
print([k for k in range(320) if ok(k)]) # Michael S. Branicky, Feb 20 2022
CROSSREFS
Cf. A000005 (d), A004086 (R).
Intersection of A029742 and A062895.
Sequence in context: A302440 A031060 A120129 * A354745 A341329 A109019
KEYWORD
base,nonn,easy
AUTHOR
Daniel Tsai, Feb 18 2022
STATUS
approved