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A091967 a(n) = n-th term of sequence A_n. 6
1, 2, 1, 0, 2, 3, 0, 6, 6, 4, 44, 1, 180, 42, 16, 1096, 7652, 13781, 8, 24000, 119779, 458561, 152116956851941670912, 1054535, -53, 26, 27, 59, 4806078, 2, 35792568, 3010349, 2387010102192469724605148123694256128, 2, 0, -53, 43, 0, -4097, 173, 37338, 111111111111111111111111111111111111111111 (list; graph; refs; listen; history; text; internal format)



This version ignores the offset of A_n and just counts from the beginning of the terms shown in the OEIS entry.

Thus a(8) = 6 because A_8 begins 1,1,2,2,3,4,5,6,... [even though A_8(8) is really 7].

If the sequence were defined up to n=91966, then the value of a(91967) could be chosen at will. However, the sequence is undefined from n=53 on, since A000053 has only 29 terms. It seems that ALL finite sequences A_n listed in the OEIS as of today, at least all those which are completely known, have fewer than n terms, cf. link. The sequence may also change each time an additional initial term is prefixed to some other sequence, which happens quite frequently in the OEIS. - M. F. Hasler, Sep 22 2013

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. The next term does not exist. - M. F. Hasler, Sep 22 2013


M. F. Hasler, Table of n, a(n) for n = 1..46 (including conjectured value of a(43) yet to be proved) - Jan 30 2009

E. M. Rains and N. J. A. Sloane, On Cayley's Enumeration of Alkanes (or 4-Valent Trees)., J. Integer Sequences, Vol. 2 (1999), Article 99.1.1.

OEIS, List of finite sequences, sorted by A-number.

N. J. A. Sloane, My favorite integer sequences, in Sequences and their Applications (Proceedings of SETA '98).

N. J. A. Sloane, Online Encyclopedia of Integer Sequences


a(26) = 26 because the 26-th term of A000026 = 26


See A051070, A107357, A102288 for other versions.

Cf. A000001, A000002, A000003, A000004, A000005, A000006, A000007, A000008, A000009, A000010, A000011, A000012, A000013, A000014, A000015, etc.

Sequence in context: A144219 A144027 A019591 * A031135 A037181 A051070

Adjacent sequences:  A091964 A091965 A091966 * A091968 A091969 A091970




Proposed by several people, including Jeff Burch and Michael Joseph Halm


Corrected and extended by Jud McCranie. Further extended by N. J. A. Sloane and E. M. Rains Dec 08 1998.

Corrected and extended by N. J. A. Sloane, May 25, 2005

a(43) is presently unknown, since A000043(43) is the exponent of the 43rd Mersenne prime. a(44) = 413927966. - N. J. A. Sloane, May 25 2005

Corrected a(26), a(36) and a(42). - M. F. Hasler, Jan 30 2009



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Last modified December 20 19:29 EST 2014. Contains 252289 sequences.