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.

A377273 Starts of runs of 3 consecutive integers that are terms in A377209.

Original entry on oeis.org

1, 2, 3, 4, 231700599, 1069467839, 1156703470, 1241186868, 2533742848, 2684864798, 3037193808, 5056780650, 7073145000, 7557047134, 9623855878, 12090760318, 12120887700, 13816479742, 14430478270, 15811947072, 16864260048, 20905152190, 22735441078, 23224253128, 23269229774, 23766221400, 25175490262
Offset: 1

Views

Author

Amiram Eldar, Oct 22 2024

Keywords

Examples

			231700599 is a term since 231700599, 231700600 and 231700601 are all terms in A377209: 231700599/A007895(231700599) = 17823123 and 17823123/A007895(17823123) = 1980347 are integers, 231700600/A007895(231700600) = 23170060 and 23170060/A007895(23170060) = 2317006 are integers, and 231700601/A007895(231700601) = 21063691 and 21063691/A007895(21063691) = 1914881 are integers.
		

Crossrefs

Cf. A007895, A376794 (binary analog).
Subsequence of A328208, A328209, A328210, A377209 and A377271.

Programs

  • PARI
    zeck(n) = if(n<4, n>0, my(k=2, s, t); while(fibonacci(k++)<=n, ); while(k && n, t=fibonacci(k); if(t<=n, n-=t; s++); k--); s); \\ Charles R Greathouse IV at A007895
    is1(k) = {my(z = zeck(k)); !(k % z) && !((k/z) % zeck(k/z)); }
    lista(kmax) = {my(q1 = is1(1), q2 = is1(2), q3); for(k = 3, kmax, q3 = is1(k); if(q1 && q2 && q3, print1(k-2, ", ")); q1 = q2; q2 = q3);}