A067185 -id:A067185 - cp's OEIS frontend

A178570 Numbers k such that prime(k+1) == 1 (mod (prime(k+2) - prime(k))).

2, 3, 5, 7, 13, 20, 24, 26, 28, 30, 31, 32, 36, 41, 43, 49, 52, 62, 64, 67, 69, 73, 77, 81, 83, 86, 87, 89, 103, 105, 109, 116, 121, 129, 135, 142, 144, 148, 152, 156, 158, 159, 163, 168, 171, 173, 182, 190, 192, 196, 206, 208, 212, 215, 217, 219, 223, 225, 231, 234, 236

Offset: 1

Juri-Stepan Gerasimov, Jan 01 2011

nonn

			2 is a term because prime(2+1) mod (prime(2+2) - prime(2)) = 5 mod 4 = 1.

G. C. Greubel, Table of n, a(n) for n = 1..10000

Cf. A067185.

fQ[n_] := Mod[Prime[n+1], Prime[n+2] - Prime[n]] == 1; Select[ Range@ 250, fQ]

isok(n) = prime(n+1) % (prime(n+2) - prime(n)) == 1; \\ Michel Marcus, Jan 31 2019

A069468 Number of ways writing n! as a product of some other numbers which has no digits equal to 1.

Original entry on oeis.org

0, 1, 3, 17, 68, 807, 5310, 121536, 2775630, 48782385, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0

Offset: 1

Labos Elemer, Mar 25 2002

			n=4, 4!=24, A067734(24)=17 and the 17 solutions are as follows: {38,46,64,83,226,234,243,262,324,342,423,432,622,2223,2232,2322,3222}.

Cf. A067734, A000142, A068183, A068185.

a(n) = A067734(n!) = A067734(A000142(n)).

a(n) = 0 if n>10 since A068184 and A067185 are complete sequences.

More terms from Max Alekseyev, Sep 19 2009

cp's OEIS Frontend

A178570 Numbers k such that prime(k+1) == 1 (mod (prime(k+2) - prime(k))).

Views

Author

Keywords

Examples

Links

Crossrefs

Programs

Mathematica

PARI