A195629 Sequence with chaotic first differences: a(1)=2; a(n)=prime((prime(n) mod 10)+pi(a(n-1))).

2, 7, 23, 53, 59, 71, 103, 151, 167, 223, 227, 263, 269, 281, 331, 349, 401, 409, 449, 457, 467, 541, 563, 613, 653, 659, 677, 733, 797, 821, 859, 863, 919, 983, 1039, 1049, 1093, 1109, 1171, 1193, 1259, 1277, 1279, 1291, 1327, 1429, 1433, 1451, 1489, 1559, 1579, 1627, 1637, 1657, 1709, 1733, 1801, 1811, 1873, 1877, 1901

Offset

1,1

Comments

Sequence with chaotic first differences; minimal values a(n)-a(n-1)=2 occur when prime(n) ==1 mod 10 and a(n-1) is lesser of twin primes (and a(n) the larger of twin primes); corresponding n's are 42, 81, 109, 114, 151, 159, 166, 172, 232, 239, 334, 343, 369, 398, 431, 522, 537, 574, 584, 651, 661, 672, 763, 770, 851, 858, 869, 872, 895, 942.

Links

Table of n, a(n) for n=1..61.

Example

n=2: prime(2)=3, A=(prime(n) mod 10)=3; a(n-1)=2, B=pi(a(n-1))=1; prime(A+B)=prime(3+1)=7 => a(2)=7;
n=3: A=4; B=5; prime(9)=23 => a(3)=23.

Crossrefs

Sequence in context: A049001 A049002 A247197 * A323526 A011757 A121963

Adjacent sequences: A195626 A195627 A195628 * A195630 A195631 A195632

Keyword

nonn

Author

Zak Seidov, Sep 24 2011

Extensions

Typos in sequence name and comments fixed by Zak Seidov, Nov 01 2011

Status

approved