A061746 a(0) = 1; a(n) is obtained by incrementing each digit of a(n-1) by 7.

1, 8, 15, 812, 1589, 8121516, 1589812813, 8121516158915810, 158981281381215168121587, 8121516158915810158981281315898121514, 158981281381215168121587812151615891581081215161589812811

Offset: 0

Author

Amarnath Murthy, May 08 2001

Keywords

• base
• nonn

Comments

In A061511-A061522, A061746-A061750 when the incremented digit exceeds 9 it is written as a 2-digit string. So 9+1 becomes the 2-digit string 10, etc.

Considering each term as a sequence of digits, the subsequences a(2n) and a(2n-1) converge to two different fixed points of the operation repeated twice, 158981281381... and 81215161589158.... - M. F. Hasler, Jun 24 2016

Links

• Harvey P. Dale, Table of n, a(n) for n = 0..16

Crossrefs

Cf. A061747 - A061750, A061511 - A061522; A061581 - A061587.

Programs

Mathematica

NestList[FromDigits[Flatten[IntegerDigits/@(IntegerDigits[#]+7)]]&,1,10] (* Harvey P. Dale, Jun 07 2025 *)

PARI

A061746(n=1, a=1, m=7)={for(n=1, n, a=eval(concat(apply(t->Str(t+m), digits(a))))); a} \\ If only the 2nd argument is given, then the operation is applied once to that argument. - M. F. Hasler, Jun 24 2016

Extensions

More terms from Larry Reeves (larryr(AT)acm.org), May 11 2001