A381585 Starts of runs of 5 consecutive integers that are all terms in A381581.

57744971, 159104411, 203738652, 212548572, 260463851, 361823291, 413644572, 431577521, 440353328, 520800012, 717222337, 726300972, 779825648, 843559091, 913313321, 945016812, 986681527, 1091786528, 1116032201, 1185786431, 1318751081, 1347208812, 1360423692, 1418212627

Offset

1,1

Comments

Are there 6 consecutive integers that are all terms in A381581?

Links

Amiram Eldar, Table of n, a(n) for n = 1..130

Example

57744971 is a term since A291711(57744971) = 17 divides 57744971, A291711(57744972) = 18 divides 57744972, A291711(57744973) = 13 divides 57744973, A291711(57744974) = 14 divides 57744974, and A291711(57744975) = 15 divides 57744975.

Prog

(PARI) mx = 20; fvec = vector(mx, i, fibonacci(2*i)); f(n) = if(n <= mx, fvec[n], fibonacci(2*n));
is1(n) = {my(s = 0, m = n, k); while(m > 0, k = 1; while(m > f(k), k++); if(m < f(k), k--); if(m >= 2*f(k), s += 2; m -= 2*f(k), s++; m -= f(k))); !(n % s); }
list(lim) = {my(q1 = is1(1), q2 = is1(2), q3 = is1(3), q4 = is1(4), s5); for(k = 5, lim, q5 = is1(k); if(q1 && q2 && q3 && q4 && q5, print1(k-4, ", ")); q1 = q2; q2 = q3; q3 = q4; q4 = q5); }

Crossrefs

Cf. A291711.

Subsequence of A381581, A381582, A381583 and A381584.

Similar sequences: A330928, A334373, A364220, A364383.

Sequence in context: A234759 A172593 A258422 * A172679 A034612 A015355

Adjacent sequences: A381582 A381583 A381584 * A381586 A381587 A381588

Keyword

nonn,base

Author

Amiram Eldar, Feb 28 2025

Status

approved