A255419 Row 9 of Ludic array A255127.

25, 167, 311, 457, 599, 745, 883, 1033, 1181, 1321, 1469, 1615, 1753, 1903, 2041, 2191, 2339, 2483, 2623, 2773, 2911, 3059, 3211, 3353, 3493, 3637, 3781, 3929, 4067, 4217, 4367, 4507, 4657, 4795, 4937, 5087, 5227, 5377, 5527, 5665, 5813, 5957, 6101, 6241, 6389, 6535, 6683, 6821, 6971, 7111

Offset

1,1

Comments

This is the first row in A255127 that starts with a composite number.

Links

Antti Karttunen, Table of n, a(n) for n = 1..10001

Formula

a(n) = a(n-P) + S = a((n-1)%P + 1) + S*floor((n-1)/P) with period P = 2027520 = A377469(9) and shift S = 293543250 = A376237(10). - M. F. Hasler, Nov 17 2024

Prog

(Scheme) (define (A255419 n) (A255127bi 9 n)) ;; Code for A255127bi given in A255127.
(PARI) my(L=vector(97847750, x, 3*x+1+x%2), m(n, k)=2^(n\/k*k)\(2^k-1)); for(i=3, 8, L=vecextract(L, 2^#L-m(#L, L[1])-1)); L255419=vecextract(L, m(#L, L[1]));
\\ If only terms up to N < P are needed, the vector L above can be chosen shorter
A255419(n, P=2027520)=n--\P*293543250 + L255419[n%P+1] \\ M. F. Hasler, Nov 17 2024
(Python) # if only terms up to a smaller limit S are needed, then S can be decreased
def A255419(n, S=293543250, P=2027520):
    try: n -= 1; return A255419.L[n]
    except IndexError: return A255419.L[n%P] + n//P*S
    except AttributeError: L = [x+5-x%2 for x in range(0, S, 3)]
    while (k:=L[0]) < 25: L = [x for i, x in enumerate(L) if i%k]
    A255419.L = L[::k]; return A255419(n+1) # M. F. Hasler, Nov 17 2024

Crossrefs

Row 9 of A255127. See A255413 - A255418 for rows 3 through 8.

Sequence in context: A317728 A125335 A126493 * A324899 A338892 A360280

Adjacent sequences: A255416 A255417 A255418 * A255420 A255421 A255422

Keyword

nonn

Author

Antti Karttunen, Feb 22 2015

Status

approved