cp's OEIS Frontend

A006507 a(n+1) = a(n) + sum of digits of a(n), with a(1)=7.

%I A006507 M4348 #32 Apr 21 2023 11:37:54
%S A006507 7,14,19,29,40,44,52,59,73,83,94,107,115,122,127,137,148,161,169,185,
%T A006507 199,218,229,242,250,257,271,281,292,305,313,320,325,335,346,359,376,
%U A006507 392,406,416,427,440,448,464,478,497,517,530,538,554,568
%N A006507 a(n+1) = a(n) + sum of digits of a(n), with a(1)=7.
%C A006507 a(n) = A004207(n+4) for n > 11. - _Reinhard Zumkeller_, Oct 14 2013
%D A006507 Editorial Note, Popular Computing (Calabasas, CA), Vol. 4 (No. 37, Apr 1976), p. 12.
%D A006507 GCHQ, The GCHQ Puzzle Book, Penguin, 2016. See page 36.
%D A006507 D. R. Kaprekar, Puzzles of the Self-Numbers. 311 Devlali Camp, Devlali, India, 1959.
%D A006507 D. R. Kaprekar, The Mathematics of the New Self Numbers, Privately Printed, 311 Devlali Camp, Devlali, India, 1963.
%D A006507 Jeffrey Shallit, personal communication.
%D A006507 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H A006507 Reinhard Zumkeller, <a href="/A006507/b006507.txt">Table of n, a(n) for n = 1..10000</a>
%H A006507 D. R. Kaprekar, <a href="/A003052/a003052_2.pdf">The Mathematics of the New Self Numbers</a> [annotated and scanned]
%H A006507 <a href="/index/Coi#Colombian">Index entries for Colombian or self numbers and related sequences</a>
%F A006507 a(n) = A062028(a(n-1)) for n > 1. - _Reinhard Zumkeller_, Oct 14 2013
%t A006507 NestList[#+Total[IntegerDigits[#]]&,7,50] (* _Harvey P. Dale_, Jan 25 2021 *)
%o A006507 (Haskell)
%o A006507 a006507 n = a006507_list !! (n-1)
%o A006507 a006507_list = iterate a062028 7  -- _Reinhard Zumkeller_, Oct 14 2013
%Y A006507 Cf. A016052, A007618, A016096.
%K A006507 base,nonn
%O A006507 1,1
%A A006507 _N. J. A. Sloane_
%E A006507 More terms from _Robert G. Wilson v_