A277338 - OEIS

%I #36 Nov 30 2016 06:11:01

%S 295,887,1675,7436,13783,52514,94039,187088,1067869,10755470,18211171,

%T 35322452,60744805,111589511,227574622,454050344,897100798,1794102596,

%U 8746117567,16403234045,70446464506,130992928913,450822227944,900544455998,1800098901007,8801197801088,17602285712176,84724043932847,159547977975595

%N Reverse and Add! sequence starting with 295.

%C Apart from the initial term in both sequences, the same as A006960.

%C a(0) = 295; a(n+1) = a(n) + A004086(a(n)).

%C 295 is conjectured to be the second smallest initial term which does not lead to a palindrome. Also, 196 is possibly the smallest initial term which does not lead to a palindrome. a(0) = 196 is described in A006960.

%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Lychrel_number">Lychrel number</a>

%F a(n) = A006960(n) for n >= 1.

%F a(n) = A243238(295, n+1). - _Felix Fröhlich_, Nov 20 2016

%e a(0) = 295

%e a(1) = 295 + 592 = 887

%e a(2) = 887 + 788 = 1675

%e ...

%p with(StringTools):

%p revnum := proc (n)

%p local a, b, c;

%p description "to REVerse the digits of a NUMber";

%p a := convert(n, string);

%p b := Reverse(a);

%p c := convert(b, decimal, 10)

%p end proc;

%p f := 0;

%p e := 295;

%p count := 0;

%p while f <> e do

%p e := e+f;

%p f := revnum(e);

%p count := count+1

%p end do;

%t a[1] = 295; a[n_] := a[n] = FromDigits@ Reverse@ IntegerDigits@ # + # &@ a[n - 1]; Array[a, 29] (* _Michael De Vlieger_, Oct 14 2016 *)

%o (PARI) terms(n) = my(x=295, i=0); while(1, print1(x, ", "); x=x+eval(concat(Vecrev(Str(x)))); i++; if(i==n, break))

%o /* Print initial 30 terms as follows: */

%o terms(30) \\ _Felix Fröhlich_, Nov 15 2016

%Y Cf. A004086.

%Y Almost the same as A006960.

%Y See index entries at A023108.

%K nonn,base

%O 0,1

%A _Matt C. Anderson_, Oct 09 2016