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.

Showing 1-2 of 2 results.

A113884 Pentanacci analog of A055502.

Original entry on oeis.org

0, 2, 3, 7, 13, 29, 59, 113, 223, 439, 877, 1721, 3389, 6653, 13093, 25741, 50599, 99487, 195581, 384509, 755959
Offset: 0

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Author

Jonathan Vos Post, Jan 27 2006

Keywords

Comments

This is to the pentanacci sequence as A055502 is to the Fibonacci sequence and A113823 is to the tribonacci sequence (i.e., least prime greater than the sum of the previous 2 terms in A055502, least prime greater than the sum of the previous 3 terms in A113823, least prime greater than the sum of the previous 5 terms in this sequence).

Examples

			a(6) = 59 because a(1)+a(2)+a(3)+a(4)+a(5) = 2+3+7+13+29 = 54, the smallest prime beyond 54 is 59.
a(10) = 877 because a(5)+a(6)+a(7)+a(8)+a(9) = 29 + 59 + 113 + 223 + 439 = 863 is prime, the next prime being 14 more, namely 877.

Crossrefs

Cf. A055502, A113823.

Formula

a(-n) = a(0) = 0, a(1) = 2, for n>1: a(n) = smallest prime > a(n-1)+a(n-2)+a(n-3)+a(n-4)+a(n-5).

A113843 Tetranacci analog of A055502.

Original entry on oeis.org

0, 2, 3, 7, 13, 29, 53, 103, 199, 389, 751, 1447, 2789, 5381, 10369, 19991, 38543, 74287, 143197, 276019, 532061, 1025579, 1976857, 3810517, 7345031, 14158009, 27290429, 52604017, 101397487, 195449957, 376741891, 726193373, 1399782719, 2698167947, 5200885961
Offset: 0

Views

Author

Jonathan Vos Post, Jan 24 2006

Keywords

Comments

This is to the tribonacci sequence as A055502 is to the Fibonacci sequence and A113823 is to the tribonacci sequence (i.e., least prime greater than the sum of the previous 2 terms in A055502, least prime greater than the sum of the previous 3 terms in A113823, least prime greater than the sum of the previous 4 terms in this sequence).

Examples

			a(15) = 19991 because a(11)+a(12)+a(13)+a(14) = 1447 + 2789 + 5381 + 10369 = 19986 and 19991 is the smallest prime > 19986.

Links

Crossrefs

Cf. A055502, A113823.

Programs

  • Mathematica
    nxt[{a_,b_,c_,d_}]:={b,c,d,NextPrime[a+b+c+d]}; Transpose[ NestList[ nxt,{0,2,3,7},40]][[1]] (* Harvey P. Dale, Sep 18 2013 *)

Formula

a(-n) = a(0) = 0, a(1) = 2, for n>1: a(n) = smallest prime > a(n-1)+a(n-2)+a(n-3)+a(n-4).

Extensions

More terms from Harvey P. Dale, Sep 18 2013
Showing 1-2 of 2 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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