A085764 Least integer m such that between m and 2m there are n palindromes.

10, 1, 2, 3, 4, 51, 61, 66, 76, 86, 96, 111, 121, 131, 141, 157, 167, 177, 187, 197, 202, 212, 222, 232, 242, 258, 268, 278, 288, 298, 303, 313, 323, 333, 343, 359, 369, 379, 389, 399, 404, 414, 424, 434, 444, 460, 470, 480, 490, 500, 501, 5101, 5201, 5301

Offset

1,1

Comments

Dean Hickerson showed that this sequence is infinite.

Links

Michael S. Branicky, Table of n, a(n) for n = 1..1000

Prog

(Python)
def ispal(n): s = str(n); return s == s[::-1]
def a(n):
    m, cm = 1, 2
    while cm != n:
        cm = cm - ispal(m) + ispal(2*m+1) + ispal(2*m+2)
        m += 1
    return m
print([a(n) for n in range(1, 55)]) # Michael S. Branicky, Oct 01 2021

Crossrefs

Cf. A002113, A085763.

Sequence in context: A240962 A376301 A324282 * A090555 A283393 A359736

Adjacent sequences: A085761 A085762 A085763 * A085765 A085766 A085767

Keyword

nonn,base

Author

Jason Earls and Amarnath Murthy, Jul 22 2003

Extensions

More terms from Jason Earls, Jul 24 2003

Status

approved