A006507 - OEIS

A006507

a(n+1) = a(n) + sum of digits of a(n), with a(1)=7.
(Formerly M4348)

7, 14, 19, 29, 40, 44, 52, 59, 73, 83, 94, 107, 115, 122, 127, 137, 148, 161, 169, 185, 199, 218, 229, 242, 250, 257, 271, 281, 292, 305, 313, 320, 325, 335, 346, 359, 376, 392, 406, 416, 427, 440, 448, 464, 478, 497, 517, 530, 538, 554, 568

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

a(n) = A004207(n+4) for n > 11. - Reinhard Zumkeller, Oct 14 2013

REFERENCES

Editorial Note, Popular Computing (Calabasas, CA), Vol. 4 (No. 37, Apr 1976), p. 12.

GCHQ, The GCHQ Puzzle Book, Penguin, 2016. See page 36.

D. R. Kaprekar, Puzzles of the Self-Numbers. 311 Devlali Camp, Devlali, India, 1959.

D. R. Kaprekar, The Mathematics of the New Self Numbers, Privately Printed, 311 Devlali Camp, Devlali, India, 1963.

Jeffrey Shallit, personal communication.

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

D. R. Kaprekar, The Mathematics of the New Self Numbers [annotated and scanned]

Index entries for Colombian or self numbers and related sequences

FORMULA

a(n) = A062028(a(n-1)) for n > 1. - Reinhard Zumkeller, Oct 14 2013

MATHEMATICA

NestList[#+Total[IntegerDigits[#]]&, 7, 50] (* Harvey P. Dale, Jan 25 2021 *)

PROG

(Haskell)

a006507 n = a006507_list !! (n-1)

a006507_list = iterate a062028 7 -- Reinhard Zumkeller, Oct 14 2013

CROSSREFS

Cf. A016052, A007618, A016096.

Sequence in context: A070792 A178893 A340162 * A257584 A035404 A003863

Adjacent sequences: A006504 A006505 A006506 * A006508 A006509 A006510

KEYWORD

base,nonn

AUTHOR

N. J. A. Sloane

EXTENSIONS

More terms from Robert G. Wilson v

STATUS

approved