A070937 Number of times maximal coefficient (A025591) appears in Product_{k<=n} (x^k + 1), i.e., number of times highest value appears in n-th row of A053632 or n-th column of A070936.

1, 2, 4, 1, 5, 6, 4, 5, 1, 4, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1

Offset

0,2

Links

Table of n, a(n) for n=0..104.

Index entries for linear recurrences with constant coefficients, signature (1,-1,1).

Formula

If n mod 4 = 0 or 3 then a(n) odd, otherwise a(n) even.

For n > 9: a(n) = A014695(n).

From Chai Wah Wu, Apr 10 2021: (Start)

a(n) = a(n-1) - a(n-2) + a(n-3) for n > 12.

G.f.: (2*x^12 - 2*x^11 + 6*x^10 - 4*x^9 + 6*x^8 - 2*x^7 - 2*x^6 + 2*x^5 - 6*x^4 + 2*x^3 - 3*x^2 - x - 1)/((x - 1)*(x^2 + 1)). (End)

Example

a(4)=5 since Product_{k<=4} (x^k + 1) = 1 + x + x^2 + 2x^3 + 2x^4 + 2x^5 + 2x^6 + 2x^7 + x^8 + x^9 + x^10 and 2 appears as a coefficient 5 times.

Crossrefs

Sequence in context: A021418 A283741 A094640 * A278437 A175036 A177985

Adjacent sequences: A070934 A070935 A070936 * A070938 A070939 A070940

Keyword

nonn,easy

Author

Henry Bottomley, May 12 2002

Status

approved