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 A053701 Vertically symmetric numbers. 12
 0, 1, 8, 11, 25, 52, 88, 101, 111, 181, 205, 215, 285, 502, 512, 582, 808, 818, 888, 1001, 1111, 1251, 1521, 1881, 2005, 2115, 2255, 2525, 2885, 5002, 5112, 5252, 5522, 5882, 8008, 8118, 8258, 8528, 8888, 10001, 10101, 10801, 11011, 11111, 11811 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS Numbers that are symmetric about a vertical mirror. 2 and 5 are taken as mirror images (as on calculator displays). LINKS Michael S. Branicky, Table of n, a(n) for n = 1..10000 (terms 1..2500 from Nathaniel Johnston) MAPLE compdig := proc(n) if(n=2)then return 5: elif(n=5)then return 2: elif(n=0 or n=1 or n=8)then return n: else return -1: fi: end: isA053701 := proc(n) local d, l, j: d:=convert(n, base, 10): l:=nops(d): for j from 1 to ceil(l/2) do if(not d[j]=compdig(d[l-j+1]))then return false: fi: od: return true: end: for n from 0 to 10000 do if(isA053701(n))then printf("%d, ", n): fi: od: # Nathaniel Johnston, May 17 2011 PROG (Python) from itertools import count, islice, product def lr(s): return s[::-1].translate({ord('2'):ord('5'), ord('5'):ord('2')}) def A053701gen(): # generator of terms yield from [0, 1, 8] for d in count(2): for first in "1258": for rest in product("01258", repeat=d//2-1): left = first + "".join(rest) for mid in [[""], ["0", "1", "8"]][d%2]: yield int(left + mid + lr(left)) print(list(islice(A053701gen(), 45))) # Michael S. Branicky, Jul 09 2022 CROSSREFS Cf. A000787, A007284, A018846 (strobogrammatic numbers). Sequence in context: A291664 A318347 A195160 * A029615 A051791 A243975 Adjacent sequences: A053698 A053699 A053700 * A053702 A053703 A053704 KEYWORD nonn,base AUTHOR Henry Bottomley, Feb 14 2000 EXTENSIONS More terms from Larry Reeves (larryr(AT)acm.org), Oct 01 2001 STATUS approved

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Last modified September 22 23:58 EDT 2023. Contains 365532 sequences. (Running on oeis4.)