"CODE" 35190;
  "COMMENT" COMPUTATION OF I[A](X),   , I[N+A](X);
  "PROCEDURE" BESS IAPLUSN(A, X, N, IA); "VALUE" A, X, N;
  "INTEGER" N; "REAL" X, A; "ARRAY" IA;
  "IF" X= 0 "THEN"
  "BEGIN" IA[0]:= "IF" A= 0 "THEN" 1 "ELSE" 0;
    "FOR" N:= N "STEP" -1 "UNTIL" 1 "DO" IA[N]:= 0
  "END" "ELSE" "IF" A= 0 "THEN"
  "BEGIN"
    BESS I(X, N, IA);
  "END" "ELSE" "IF" A= .5 "THEN"
  "BEGIN" "REAL" C;
    C:= .797 884 560 802 865 * SQRT(ABS(X)) * EXP (ABS (X));
    NONEXP SPHER BESSI(X, N, IA);
    "FOR" N:= N "STEP" -1 "UNTIL" 0 "DO" IA[N]:= C*IA[N]
  "END" "ELSE"
  "BEGIN" "REAL" EXPX;
    EXPX:= EXP(ABS(X));
    NONEXP BESS IAPLUSN(A, X, N, IA);
    "FOR" N:= N "STEP" -1 "UNTIL" 0 "DO" IA[N]:= EXPX * IA[N]
  "END" BESS IAPLUSN;
        "EOP"