A034971 a(n) = floor(E_(n+1)/E_(n)) where E_n is n-th Euler number (see A028296 and A000364).

5, 12, 22, 36, 53, 73, 97, 124, 154, 187, 223, 263, 306, 352, 402, 454, 510, 569, 632, 697, 766, 838, 914, 992, 1074, 1159, 1248, 1339, 1434, 1532, 1634, 1738, 1846, 1957, 2071, 2189, 2310, 2434, 2561, 2691, 2825, 2962, 3102, 3246, 3393, 3542, 3696, 3852

Offset: 1

Author

Labos Elemer

Keywords

• nonn
• easy

Comments

First nine terms are identical to those of A025740.

References

• J. Peters J. and J. Stein, Mathematische Tafeln. Revised Russian Edition in 1968, Moscow, Table 9b.

Crossrefs

Cf. A028296, A000364, A025740.

Programs

Mathematica

Wolfram: ae[ x_ ] := Abs[ EulerE[ 2*x ] ] and fo[ x_ ] := Floor[ N[ ae[ x ]/ae[ x-1 ], 80 ] ]
Table[Floor[Abs[EulerE[2n+2]]/Abs[EulerE[2n]]],{n,60}] (* Harvey P. Dale, May 01 2011 *)

Formula

a(n) = floor(E(n+1)/E(n)) where E(n) is the n-th coefficient in the expansion of sec(x).