cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A007398 Add 7, then reverse digits.

Original entry on oeis.org

0, 7, 41, 84, 19, 62, 96, 301, 803, 18, 52, 95, 201, 802, 908, 519, 625, 236, 342, 943, 59, 66, 37, 44, 15, 22, 92, 99, 601, 806, 318, 523, 35, 24, 13, 2, 9, 61, 86, 39, 64, 17, 42, 94, 101, 801, 808, 518, 525, 235, 242, 942, 949, 659, 666, 376, 383, 93, 1, 8, 51, 85, 29, 63
Offset: 0

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Comments

From n = 1 the sequence is periodic with a period of 63. The Data without the initial 0 gives that period. - David A. Corneth, Aug 01 2018

References

  • J. Roberts, Lure of the Integers, Math. Assoc. America, 1992, p. 15.
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Cf. A117828.

Programs

  • Maple
    rev:=proc(n) local nn, nnn: nn:=convert(n,base,10): add(nn[nops(nn)+1-j]*10^(j-1),j=1..nops(nn)) end: a[0]:=0: for n from 1 to 70 do a[n]:=rev(7+a[n-1]) od: seq(a[n],n=0..70); # Emeric Deutsch, Jul 28 2006
  • Mathematica
    NestList[FromDigits[Reverse[IntegerDigits[# + 7]]]&, 0, 60] (* Vincenzo Librandi, Aug 08 2017 *)
  • PARI
    first(n) =  my(res = vector(n)); res[1]=0; for(i = 2, n, res[i] = fromdigits(Vecrev(digits(res[i - 1] + 7)))); res \\ David A. Corneth, Aug 01 2018

Extensions

More terms from Emeric Deutsch, Jul 28 2006