A015979 - OEIS

A015979

Three iterations of Reverse and Add are needed to reach a palindrome.

59, 68, 77, 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, 353, 354, 355, 356, 362, 363, 366, 376, 382, 383, 384, 389, 392, 397

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OFFSET

1,1

COMMENTS

The number of iterations starts at 1, so palindromes (cf. A002113) are not excluded. The corresponding sequence excluding palindromes is A065208.

LINKS

Robert Israel, Table of n, a(n) for n = 1..10000

Index entries for sequences related to Reverse and Add!

MAPLE

filter:= proc(n, t) local x, d, m, L, i;

x:= n;

L:= convert(x, base, 10);

for i from 1 to t do

d:= nops(L);

x:= add(L[i]*(10^(i-1) + 10^(d-i)), i=1..d);

L:= convert(x, base, 10);

if L = ListTools:-Reverse(L) then return (i=t) fi;

od;

false

end proc:

select(filter, [$1..1000], 3); # Robert Israel, Aug 26 2024

CROSSREFS

Cf. A002113, A065208.

Sequence in context: A096339 A216872 A235225 * A065208 A061759 A061764

Adjacent sequences: A015976 A015977 A015978 * A015980 A015981 A015982

KEYWORD

nonn,base

AUTHOR

Robert G. Wilson v

EXTENSIONS

Offset corrected by Robert Israel, Aug 26 2024

STATUS

approved