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 A065208 Three 'Reverse and Add' steps are needed to reach a palindrome. 3
 59, 68, 86, 95, 155, 156, 157, 158, 164, 165, 168, 178, 180, 184, 185, 186, 194, 199, 249, 254, 255, 256, 257, 263, 264, 267, 277, 283, 284, 285, 293, 298, 299, 348, 349, 354, 355, 356, 362, 366, 376, 382, 384, 389, 392, 397, 398, 399, 439, 447, 448, 449, 452, 453, 455, 461, 462, 465, 475, 481, 482, 483, 488, 489, 491, 496, 497, 498, 499, 538, 546, 547, 548, 551, 552, 553, 554, 560, 561, 564, 574, 580, 581, 582, 587, 588, 590, 596, 597, 598, 637, 645, 647, 650, 651, 652, 653, 660, 663, 673, 680, 681, 687, 694, 695, 697, 736, 744, 745, 746, 750 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS The number of steps starts at 0, so palindromes (cf. A002113) are excluded. LINKS Harry J. Smith, Table of n, a(n) for n=1,...,1000 MATHEMATICA palQ[n_]:=Module[{idn=IntegerDigits[n]}, idn==Reverse[idn]] tst[n_]:=palQ/@NestList[#+FromDigits[Reverse[IntegerDigits[#]]]&, n, 3]=={False, False, False, True} Select[Range[750], tst] (* Harvey P. Dale, Nov 26 2010 *) PROG (ARIBAS): revadd_steps(3, 54). For the definition of function revadd_steps see A065206. (PARI) Rev(x)= { local(d, r=0); while (x>0, d=x-10*(x\10); x\=10; r=r*10 + d); return(r) } digitsIn(x)= { local(d); if (x==0, return(1)); d=1 + log(x)\log(10); if (10^d == x, d++, if (10^(d-1) > x, d--)); return(d) } Palin(x)= { local(d, e, f, i, t, y); if (x==0, return(1)); y=x; d=digitsIn(x); t=10^(d - 1); for (i=1, d\2, f=y-10*(y\10); y\=10; e=x\t; x-=t*e; t/=10; if (e!=f, return(0)) ); return(1) } { n=0; for (m = 0, 10^9, p=m; b=1; for (i=1, 3, if (Palin(p), b=0; break); p=Rev(p) + p); if (b && Palin(p), write("b065208.txt", n++, " ", m); if (n==1000, return)) ) } \\ Harry J. Smith, Oct 14 2009 CROSSREFS Sequence in context: A216872 A235225 A015979 * A061759 A061764 A316971 Adjacent sequences:  A065205 A065206 A065207 * A065209 A065210 A065211 KEYWORD nonn,base AUTHOR Klaus Brockhaus, Oct 21 2001 EXTENSIONS OFFSET changed from 0,1 to 1,1 by Harry J. Smith, Oct 14 2009 More terms from Harvey P. Dale, Nov 26 2010 STATUS approved

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Last modified October 14 09:25 EDT 2019. Contains 327995 sequences. (Running on oeis4.)