A291933 a(1)=2; a(n) is the sum of prime(n) and the last digit of previous term.

2, 5, 10, 7, 18, 21, 18, 27, 30, 29, 40, 37, 48, 51, 48, 61, 60, 61, 68, 79, 82, 81, 84, 93, 100, 101, 104, 111, 110, 113, 130, 131, 138, 147, 156, 157, 164, 167, 174, 177, 186, 187, 198, 201, 198, 207, 218, 231, 228, 237, 240, 239, 250, 251

Offset

1,1

Comments

All prime numbers are generated, if the last digit of a term is subtracted from the next term of the sequence.

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Formula

a(n) = prime(n) + a(n-1) mod 10, where a(0) = 0.

Example

For n = 7: a(6) = 21 with last digit 1 and prime(7) = 17. 17 + 1 = 18, so a(7) = 18.

Mathematica

FoldList[#2 + Mod[#1, 10] &, 0, Prime@ Range@ 54] (* Michael De Vlieger, Sep 18 2017 *)
nxt[{n_, a_}]:={n+1, Prime[n+1]+Mod[a, 10]}; Rest[NestList[nxt, {0, 0}, 60][[All, 2]]] (* Harvey P. Dale, May 26 2019 *)

Prog

(PARI) {p=2; print1(p", "); forprime(n=3, 300, a=n+p%10; print1(a", "); p=a)}

Crossrefs

Sequence in context: A188525 A324503 A126842 * A332198 A154680 A323728

Adjacent sequences: A291930 A291931 A291932 * A291934 A291935 A291936

Keyword

nonn,base

Author

Dimitris Valianatos, Sep 06 2017

Extensions

Removed vacuous a(0) in NAME. - R. J. Mathar, Jun 19 2021

Status

approved