A037677 Base 7 digits are, in order, the first n terms of the periodic sequence with initial period 1,0,2,3.

1, 7, 51, 360, 2521, 17647, 123531, 864720, 6053041, 42371287, 296599011, 2076193080, 14533351561, 101733460927, 712134226491, 4984939585440, 34894577098081, 244262039686567, 1709834277805971, 11968839944641800, 83781879612492601, 586473157287448207, 4105312101012137451

Offset

1,2

Links

Paolo Xausa, Table of n, a(n) for n = 1..1000

Index entries for linear recurrences with constant coefficients, signature (8,-8,8,-7).

Formula

a(n) = 8*a(n-1) - 8*a(n-2) + 8*a(n-3) - 7*a(n-4).

G.f.: ( x*(1-x+3*x^2) ) / ( (x-1)*(7*x-1)*(x^2+1) ). - R. J. Mathar, May 04 2015

a(n) = floor(3*7^n/20). - Christian Krause, Jun 06 2026

Mathematica

Quotient[3*7^Range[25], 20] (* Paolo Xausa, Jun 06 2026 *)

Crossrefs

Sequence in context: A039308 A029525 A037500 * A034354 A015555 A137382

Adjacent sequences: A037674 A037675 A037676 * A037678 A037679 A037680

Keyword

nonn,base,easy,changed

Author

Clark Kimberling

Extensions

a(20)-a(23) from Christian Krause, Jun 06 2026

Status

approved