cp's OEIS Frontend

A091967 a(n) is the n-th term of sequence A_n, ignoring the offset, or -1 if A_n has fewer than n terms.

%I A091967 #99 Aug 17 2025 16:38:12
%S A091967 0,2,1,0,2,3,0,6,6,4,44,1,180,42,16,1096,7652,13781,8,24000,119779,
%T A091967 458561,152116956851941670912,1054535,-53,26,27,59,4806078,2,35792568,
%U A091967 3010349,2387010102192469724605148123694256128,2,0,-53,43,0,-4097,173,37338,111111111111111111111111111111111111111111,30402457,413927966
%N A091967 a(n) is the n-th term of sequence A_n, ignoring the offset, or -1 if A_n has fewer than n terms.
%C A091967 This version ignores the offset of A_n and just counts from the beginning of the terms shown in the OEIS entry.
%C A091967 Thus a(8) = 6 because A_8 begins 1,1,2,2,3,4,5,6,... [even though A_8(8) is really 7].
%C A091967 The value a(n) = -1 could arise in two different ways, but it will be easy to decide which. - _N. J. A. Sloane_, Nov 27 2016
%C A091967 From _M. F. Hasler_, Sep 22 2013: (Start)
%C A091967 The value of a(91967) can be chosen at will.
%C A091967 Note that this sequence may change if the initial terms in A_n are altered, which does happen from time to time, usually because of the addition of an initial term.
%C A091967 After a(47), currently unknown, the sequence continues with a(48) = A48(47) = 1497207322929, a(49) = A49(48) = unknown, a(50) = A50(49) = unknown, a(51) = A51(50) = 1125899906842625, a(52)=97, a(53) = -1 (since A000053 has only 29 terms). (End)
%C A091967 a(58) = A000058(57) = 138752...985443 (29334988649136302 digits) is too large to include in the b-file. - _Pontus von Brömssen_, May 21 2022
%H A091967 Pontus von Brömssen, <a href="/A091967/b091967.txt">Table of n, a(n) for n = 1..57</a> (terms n = 1..46 from M. F. Hasler)
%H A091967 OEIS, <a href="/search?q=keyword:fini&amp;sort=number">List of finite sequences, sorted by A-number</a>.
%H A091967 N. J. A. Sloane, <a href="http://neilsloane.com/doc/sg.txt">My favorite integer sequences</a>, in Sequences and their Applications (Proceedings of SETA '98).
%H A091967 <a href="/index/Se#selfies">Index entries for sequences whose definition involves A_n (or An)</a>.
%e A091967 a(1) = 0 since A000001 has offset 0, and begins with A000001(0) = 0.
%e A091967 a(26) = 26 because the 26th term of A000026 = 26.
%Y A091967 See A051070, A107357, A102288 for other versions.
%Y A091967 Cf. A000001, A000002, A000003, A000004, A000005, A000006, A000007, A000008, A000009, A000010, A000011, A000012, A000013, A000014, A000015, etc.
%K A091967 sign
%O A091967 1,2
%A A091967 Proposed by several people, including _Jeff Burch_ and _Michael Joseph Halm_
%E A091967 Corrected and extended by _Jud McCranie_; further extended by _N. J. A. Sloane_ and E. M. Rains, Dec 08 1998
%E A091967 Corrected and extended by _N. J. A. Sloane_, May 25 2005
%E A091967 a(26), a(36) and a(42) corrected by _M. F. Hasler_, Jan 30 2009
%E A091967 a(43) and a(44) added by _Daniel Sterman_, Nov 27 2016
%E A091967 a(1) corrected by _N. J. A. Sloane_, Nov 27 2016 at the suggestion of _Daniel Sterman_
%E A091967 Definition and comments changed by _N. J. A. Sloane_, Nov 27 2016