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A255419 Row 9 of Ludic array A255127.

%I A255419 #17 Nov 18 2024 07:37:19
%S A255419 25,167,311,457,599,745,883,1033,1181,1321,1469,1615,1753,1903,2041,
%T A255419 2191,2339,2483,2623,2773,2911,3059,3211,3353,3493,3637,3781,3929,
%U A255419 4067,4217,4367,4507,4657,4795,4937,5087,5227,5377,5527,5665,5813,5957,6101,6241,6389,6535,6683,6821,6971,7111
%N A255419 Row 9 of Ludic array A255127.
%C A255419 This is the first row in A255127 that starts with a composite number.
%H A255419 Antti Karttunen, <a href="/A255419/b255419.txt">Table of n, a(n) for n = 1..10001</a>
%F A255419 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
%o A255419 (Scheme) (define (A255419 n) (A255127bi 9 n)) ;; Code for A255127bi given in A255127.
%o A255419 (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]));
%o A255419 \\ If only terms up to N < P are needed, the vector L above can be chosen shorter
%o A255419 A255419(n, P=2027520)=n--\P*293543250 + L255419[n%P+1] \\ _M. F. Hasler_, Nov 17 2024
%o A255419 (Python) # if only terms up to a smaller limit S are needed, then S can be decreased
%o A255419 def A255419(n, S=293543250, P=2027520):
%o A255419     try: n -= 1; return A255419.L[n]
%o A255419     except IndexError: return A255419.L[n%P] + n//P*S
%o A255419     except AttributeError: L = [x+5-x%2 for x in range(0, S, 3)]
%o A255419     while (k:=L[0]) < 25: L = [x for i, x in enumerate(L) if i%k]
%o A255419     A255419.L = L[::k]; return A255419(n+1) # _M. F. Hasler_, Nov 17 2024
%Y A255419 Row 9 of A255127. See A255413 - A255418 for rows 3 through 8.
%K A255419 nonn
%O A255419 1,1
%A A255419 _Antti Karttunen_, Feb 22 2015