A100787 - OEIS

A100787

First differences give the same sequence written as a string of individual digits.

1, 2, 4, 8, 16, 17, 23, 24, 31, 33, 36, 38, 42, 45, 46, 49, 52, 55, 61, 64, 72, 76, 78, 82, 87, 91, 97, 101, 110, 115, 117, 122, 127, 133, 134, 140, 144, 151, 153, 160, 166, 173, 181, 189, 191, 199, 206, 215, 216, 225, 232, 233, 233, 234, 235, 236, 236, 237, 238, 243

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

OFFSET

1,2

REFERENCES

E. Angelini, "Jeux de suites", in Dossier Pour La Science, pp. 32-35, Volume 59 (Jeux math'), April/June 2008, Paris.

LINKS

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

EXAMPLE

1.2.4.8.16.17.23.24.31 ... <- sequence

.1.2.4.8..1..6..1..7... <- first differences are the sequence's digits.

MAPLE

A[1]:= 1: S:= "1":

for n from 2 to 100 do

A[n]:= A[n-1] + parse(S[n-1]);

S:= cat(S, A[n]);

od:

seq(A[i], i=1..100); # Robert Israel, Jun 11 2019

MATHEMATICA

a[1] = 1; a[n_] := a[n] = a[n - 1] + Flatten[ Table[ IntegerDigits[ a[i]], {i, n - 1}]][[n - 1]]; Table[ a[n], {n, 60}] (* Robert G. Wilson v, Jun 15 2005 *)

CROSSREFS

First differences are A100880; Cf. A100787, A107974, A107975, A107976, A107977 for "seeds" 1, 3, 5, 7 and 9.

Sequence in context: A101466 A129851 A061681 * A115795 A048718 A018510

Adjacent sequences: A100784 A100785 A100786 * A100788 A100789 A100790

KEYWORD

base,easy,nonn

AUTHOR

David W. Wilson, Jan 04 2005

STATUS

approved