The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A046498 Palindromes expressible as the sum of 3 consecutive palindromes. 2
 6, 9, 66, 99, 333, 363, 393, 636, 666, 696, 939, 969, 999, 3333, 3663, 3993, 6336, 6666, 6996, 9339, 9669, 9999, 30303, 30603, 30903, 33333, 33633, 33933, 36363, 36663, 36963, 39393, 39693, 39993, 60306, 60606, 60906, 63336, 63636, 63936 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Michael S. Branicky, Table of n, a(n) for n = 1..15358 (all terms with <= 13 digits) Patrick De Geest, World!Of Numbers EXAMPLE 6666 = 2112 + 2222 + 2332. PROG (Python) from itertools import product def ispal(n): s = str(n); return s == s[::-1] def pals(d, base=10): # all d-digit palindromes digits = "".join(str(i) for i in range(base)) for p in product(digits, repeat=d//2): if d > 1 and p[0] == "0": continue left = "".join(p); right = left[::-1] for mid in [[""], digits][d%2]: yield int(left + mid + right) def auptod(dd): alst = [6, 9] last3 = [7, 8, 9] for d in range(2, dd+1): for p in pals(d): last3 = last3[1:] + [p] if ispal(sum(last3)): alst.append(sum(last3)) return alst print(auptod(5)) # Michael S. Branicky, Jun 09 2021 CROSSREFS Cf. A002113. Sequence in context: A359800 A264380 A284636 * A119738 A299917 A204383 Adjacent sequences: A046495 A046496 A046497 * A046499 A046500 A046501 KEYWORD nonn,base AUTHOR Patrick De Geest, Sep 15 1998 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified September 25 13:12 EDT 2023. Contains 365647 sequences. (Running on oeis4.)