1,3

Robert G. Wilson v, Table of n, a(n) for n = 1..94 (first 82 terms from Chai Wah Wu)

palQ[n_Integer, base_Integer] := Block[{}, Reverse[ idn = IntegerDigits[n, base]] == idn]; genPal[n_] := Block[{id = IntegerDigits@ n, insert = {{}, {0}, {1}, {2}, {3}, {4}, {5}, {6}, {7}, {8}, {9}}}, FromDigits@ Join[id, #, Reverse@ id] & /@ insert]; k = 1; lst = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}; While[k < 1000001, s = Select[ genPal[k], palQ[#, 25] &]; If[s != {}, AppendTo[lst, s]; Print@ s; lst = Sort@ Flatten@ lst]; k++]; lst

(Magma) [n: n in [0..10000000] | Intseq(n) eq Reverse(Intseq(n))and Intseq(n, 25) eq Reverse(Intseq(n, 25))]; // Vincenzo Librandi, Nov 23 2014

(Python)

from gmpy2 import digits

def palQ(n, b): # check if n is a palindrome in base b

s = digits(n, b)

return s == s[::-1]

def palQgen10(l): # unordered generator of palindromes of length <= 2*l

if l > 0:

yield 0

for x in range(1, 10**l):

s = str(x)

yield int(s+s[-2::-1])

yield int(s+s[::-1])

A250410_list = sorted([n for n in palQgen10(6) if palQ(n, 25)])

# Chai Wah Wu, Nov 25 2014

Cf. A007632, A007633, A029961, A029962, A029963, A029964, A029804, A029965, A029966, A029967, A029968, A029969, A029970, A029731, A097855, A250408, A250409, A250411, A099165, A250412.

Sequence in context: A103357 A055931 A250411 * A250409 A303002 A167152

Adjacent sequences: A250407 A250408 A250409 * A250411 A250412 A250413

nonn,base

Robert G. Wilson v, Nov 22 2014

approved