A074865 a(n) = a(n-1) + R(a(n-2)) + R(a(n-3)) + R(a(n-4)) where a(1) = a(2) = a(3) = a(4) = 1 and R(n) (A004086) is the reverse of n.

1, 1, 1, 1, 4, 7, 13, 25, 67, 157, 316, 1195, 2635, 9910, 21796, 33268, 108541, 264685, 566431, 1384927, 2251855, 10267813, 23278831, 68031385, 119376340, 223452859, 339327088, 1399568407, 3282220573, 12169858759, 23849465446, 130434244321, 294426858097

Offset: 1

Author

Felice Russo, Sep 11 2002

Keywords

• easy
• base
• nonn

Crossrefs

Cf. A000288, A004086.

Programs

Mathematica

a[1]=a[2]=a[3]=a[4]=1; R[n_]:=FromDigits[Reverse[IntegerDigits[n]]]; a[n_]:=a[n-1]+R[a[n-2]]+R[a[n-3]]+R[a[n-4]]; Array[a,32] (* Stefano Spezia, Jun 14 2023 *)

Extensions

Corrected and extended by Michel ten Voorde Jun 13 2003

More terms from Joshua Zucker, May 08 2006

Definition adapted to offset by Georg Fischer, Jun 18 2021